HK1249287B - Apparatus, method and computer readable medium for radio resource management reporting - Google Patents

Description

Apparatus, method and computer-readable medium for radio resource management reporting

Prior application

This application claims the benefit of U.S. Provisional Patent Application No. 62/161,584, filed on May 14, 2015, entitled “METHOD OF ENMANCED RRM MEASUREMENTS WITH MIMO AND IRC SUPPORT”.

Technical Field

Embodiments relate to wireless communications. Some embodiments relate to wireless networks including 3GPP (3rd Generation Partnership Project) networks, 3GPP LTE (Long Term Evolution) networks, 3GPP LTE-A (Advanced LTE) networks, and 5G networks, although the scope of the embodiments is not limited in this respect. Some embodiments relate to radio resource management (RRM) measurements made by user equipment (UE) devices and reported to cellular base stations.

Background Art

In cellular systems, when a mobile user equipment (UE) moves from one cell to another, it performs cell selection/reselection and handover operations. Furthermore, the UE performs radio resource management (RRM) measurements on the quality of reference signals sent by neighboring cells. In current Long Term Evolution (LTE) systems, the UE uses reference signals to report two parameters: Reference Signal Received Power (RSRP) and Reference Signal Received Quality (RSRQ).

RSRP provides information about the signal power from a specific cell while excluding noise and interference from other cells. RSRP is defined as the average power of resource elements (REs) carrying a cell-specific reference signal (RS) over the entire bandwidth, i.e. RSRP is measured only in symbols carrying RS. For RSRP, the UE measures the power of multiple resource elements used to transmit the reference signal and takes its average. RSRQ (Reference Signal Received Quality) provides link quality and also takes into account RSSI (Received Signal Strength Indicator) and the number of resource blocks used (N). RSRQ indicates the quality of the received reference signal including the effects of interference.

Traditional RRM measurements convey power information for both the target and interfering cells. However, this is insufficient to accurately determine link quality for more advanced receiver architectures with multiple receive antennas, especially for inter-frequency handover. Existing measurements based on RSRP are insufficient for reliable handover decisions because the MIMO dimension is lost in current measurements.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, which are not necessarily drawn to scale, like reference numerals may describe similar components in different views. Like reference numerals with different letter suffixes may represent different instances of similar components. Some embodiments are shown by way of example and not limitation in the various figures of the following drawings.

FIG1 is a functional diagram of a 3GPP network according to some embodiments.

FIG2 is a block diagram of a user equipment (UE) according to some embodiments.

3 is a block diagram of an evolved Node B (eNB) in accordance with some embodiments.

FIG4 illustrates an example of multi-beam transmission according to some embodiments.

5 is a diagram illustrating a MIMO transmission scenario using an eNB and a UE each having multiple antennas, according to some embodiments.

6 is a flow diagram illustrating an example process for enhanced RRM performed by a UE according to some embodiments.

DETAILED DESCRIPTION

The following description and accompanying drawings sufficiently illustrate the specific embodiments to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in or replaced by portions and features of other embodiments. The embodiments set forth in the claims encompass all available equivalents of those claims.

Figure 1 is a functional diagram of a 3GPP network according to some embodiments. The network includes a radio access network (RAN) (e.g., E-UTRAN or Evolved Universal Terrestrial Radio Access Network, as shown) 101 and a core network 120 (e.g., shown as an Evolved Packet Core (EPC)) coupled together via an S1 interface 115. For convenience and brevity, only the core network 120 and a portion of the RAN 101 are shown.

The core network 120 includes a mobility management entity (MME) 122, a serving gateway (serving GW) 124, and a packet data network gateway (PDN GW) 126. The RAN 101 includes an evolved Node B (eNB) 104 (which can operate as a base station) for communicating with a user equipment (UE) 102. The eNB 104 can include a macro eNB and a low power (LP) eNB. According to some embodiments, the eNB 104 can send a downlink control message to the UE 102 to indicate an allocation of physical uplink control channel (PUCCH) channel resources. The UE 102 can receive the downlink control message from the eNB 104 and can send an uplink control message to the eNB 104 in at least a portion of the PUCCH channel resources. These embodiments will be described in more detail below.

The MME 122 is functionally similar to the control plane of a traditional Serving GPRS Support Node (SGSN). The MME 122 manages mobility aspects of access, such as gateway selection and tracking area list management. The Serving GW 124 terminates the interface toward the RAN 101 and routes data packets between the RAN 101 and the core network 120. Furthermore, the Serving GW 124 can be the local mobility anchor for inter-eNB handovers and can also provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful interception, charging, and some policy enforcement. The Serving GW 124 and the MME 122 can be implemented in one physical node or in separate physical nodes. The PDN GW 126 terminates the SGi interface toward the Packet Data Network (PDN). The PDN GW 126 routes data packets between the EPC 120 and external PDNs and can be a key node for policy enforcement and charging data collection. The PDN GW 126 can also provide an anchor for mobility with non-LTE access. The external PDN may be an IP Multimedia Subsystem (IMS) domain and any kind of IP network. The PDN GW 126 and the Serving GW 124 may be implemented in one physical node or separate physical nodes.

The eNB 104 (macro and micro eNBs) terminates the air interface protocol and can be the first point of contact for the UE 102. In some embodiments, the eNB 104 can implement various logical functions for the RAN 101, including but not limited to RNC (Radio Network Controller) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. According to some embodiments, the UE 102 can be configured to communicate orthogonal frequency division multiplexing (OFDM) communication signals with the eNB 104 over a multi-carrier communication channel in accordance with an orthogonal frequency division multiple access (OFDMA) communication technique. An OFDM signal can include multiple orthogonal subcarriers.

The S1 interface 115 separates the RAN 101 and the EPC 120. The S1 interface 115 is divided into two parts: S1-U, which carries traffic data between the eNB 104 and the Serving GW 124, and S1-MME, which serves as the signaling interface between the eNB 104 and the MME 122. The X2 interface is an interface between eNBs 104. The X2 interface consists of two parts, X2-C and X2-U. X2-C is a control plane interface between eNBs 104, while X2-U is a user plane interface between eNBs 104.

For cellular networks, LP cells are typically used to extend coverage to indoor areas where outdoor signals don't reach well, or to increase network capacity in areas with high phone usage, such as train stations. The term low-power (LP) eNB, as used herein, refers to any suitable lower-power eNB used to implement narrower cells (narrower than macrocells), such as femtocells, picocells, or microcells. Femtocell eNBs are typically provided by mobile network operators to their residential or enterprise customers. Femtocells are typically the size of a residential gateway or smaller and are typically connected to a user's broadband line. Once connected, a femtocell connects to the mobile operator's mobile network and provides additional coverage for residential femtocells, typically with a range of 30 to 50 meters. Thus, an LP eNB can be a femtocell eNB because it is coupled through a PDN GW 126. Similarly, a picocell is a wireless communication system that typically covers a small area, such as within a building (office, shopping mall, train station, etc.) or, more recently, on an airplane. A picocell eNB can generally be connected to another eNB (e.g., a macro eNB) via its base station controller (BSC) functionality via an X2 link. Thus, an LP eNB can be implemented using a picocell eNB, as it is coupled to the macro eNB via the X2 interface. A picocell eNB or other LP eNB can include some or all of the functionality of a macro eNB. In some cases, this may be referred to as an access point base station or enterprise femtocell.

In some embodiments, a downlink resource grid can be used for downlink transmissions from eNB 104 to UE 102, while uplink transmissions from UE 102 to eNB 104 can utilize similar techniques. The grid can be a time-frequency grid, referred to as a resource grid or time-frequency resource grid, representing the physical resources in the downlink during each time slot. This representation of the time-frequency plane is common in OFDM systems and makes radio resource allocation intuitive. Each column and row of the resource grid corresponds to an OFDM symbol and an OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to a time slot in a radio frame. The smallest time-frequency unit in the resource grid is called a resource element (RE). Each resource grid includes multiple resource blocks (RBs), which describe the mapping of certain physical channels to resource elements. Each resource block comprises a collection of resource elements in the frequency domain and can represent the minimum amount of resources that can currently be allocated. There are several different physical downlink channels that are communicated using such resource blocks. Of particular relevance to the present disclosure, two of these physical downlink channels are a physical downlink shared channel and a physical downlink control channel.

The physical downlink shared channel (PDSCH) carries user data and higher layer signaling to the UE 102 ( FIG. 1 ). The physical downlink control channel (PDCCH) carries, among other things, information about the transport format and resource allocation associated with the PDSCH channel. The PDCCH also informs the UE 102 about the transport format, resource allocation, and hybrid automatic repeat request (HARQ) information for the uplink shared channel. Typically, downlink scheduling (e.g., allocating control and shared channel resource blocks to UEs 102 within a cell) can be performed at the eNB 104 based on channel quality information fed back from the UE 102 to the eNB 104. Downlink resource allocation information can then be sent to the UE 102 on a control channel (PDCCH) intended for (allocated to) the UE 102.

PDCCH uses CCE (control channel elements) to transmit control information. PDCCH complex symbols are first organized into quadruplets before being mapped to resource elements, and then these quadruplets are rearranged using a sub-block interleaver for rate matching. Each PDCCH is sent using one or more of these control channel elements (CCE), where each CCE corresponds to nine groups of physical resource elements, each group having four physical resource elements, and such groups are called resource element groups (REGs). Four QPSK symbols are mapped to each REG. Depending on the size of the DCI and the channel conditions, one or more CCEs can be used to send the PDCCH. Four or more different PDCCH formats can be defined in LTE, with different numbers of CCEs (e.g., aggregation levels, L=1, 2, 4, or 8).

As used herein, the term circuitry may refer to, be part of, or include an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared processor, dedicated processor, or processor group) or memory (shared processor, dedicated processor, or processor group) that executes one or more software or firmware programs, a combinational logic circuit, or other suitable hardware components that provide the functionality. In some embodiments, the circuitry may be implemented in one or more software or firmware modules, or the functionality associated with the circuitry may be implemented by one or more software or firmware modules. In some embodiments, the circuitry may include logic that is at least partially operable in hardware. The embodiments described herein may be implemented as a system using any appropriately configured hardware or software.

FIG2 is a functional diagram of a user equipment (UE) according to some embodiments. UE 200 may be suitable for use as UE 102, as shown in FIG1 . In some embodiments, UE 200 may include application circuitry 202, baseband circuitry 204, radio frequency (RF) circuitry 206, front-end module (FEM) circuitry 208, and multiple antennas 210A-210D, coupled together at least as shown. In some embodiments, other circuitry or arrangements may include one or more elements or components of application circuitry 202, baseband circuitry 204, RF circuitry 206, or FEM circuitry 208, and in some cases, may also include other elements or components. As an example, "processing circuitry" may include one or more elements or components, some or all of which may be included in application circuitry 202 or baseband circuitry 204. As another example, "transceiver circuitry" may include one or more elements or components, some or all of which may be included in RF circuitry 206 or FEM circuitry 208. However, these examples are not limiting, as in some cases, processing circuitry or transceiver circuitry may also include other elements or components.

The application circuitry 202 may include one or more application processors. For example, the application circuitry 202 may include circuitry such as, but not limited to, one or more single-core processors or multi-core processors. The processor(s) may include any combination of general-purpose processors and specialized processors (e.g., graphics processors, application processors, etc.). These processors may be coupled to and/or include memory/storage devices, and may be configured to execute instructions stored in the memory/storage devices to enable various applications and/or operating systems to run on the system.

The baseband circuitry 204 may include circuitry such as, but not limited to, one or more single-core processors or multi-core processors. The baseband circuitry 204 may include one or more baseband processors or control logic to process baseband signals received from the receive signal path of the RF circuitry 206 and generate baseband signals for the transmit signal path of the RF circuitry 206. The baseband processing circuitry 204 may interface with the application circuitry 202 to generate and process baseband signals and control the operation of the RF circuitry 206. For example, in some embodiments, the baseband circuitry 204 may include a second generation (2G) baseband processor 204a, a third generation (3G) baseband processor 204b, a fourth generation (4G) baseband processor 204c, and/or other baseband processor(s) 204d for other existing generations, generations under development, or generations to be developed (e.g., fifth generation (5G), 6G, etc.). Baseband circuitry 204 (e.g., one or more of baseband processors 204a-d) can handle various radio control functions that enable communication with one or more radio networks via RF circuitry 206. Radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency frequency shifting, and the like. In some embodiments, the modulation/demodulation circuitry of baseband circuitry 204 may include fast Fourier transform (FFT), precoding, and/or constellation mapping/demapping functions. In some embodiments, the encoding/decoding circuitry of baseband circuitry 204 may include convolution, tail-biting, turbo, Viterbi, and/or low-density parity check (LDPC) encoder/decoder functions. Embodiments of the modulation/demodulation and encoder/decoder functions are not limited to these examples and may include other suitable functions in other embodiments.

In some embodiments, the baseband circuitry 204 may include elements of a protocol stack, such as elements of the Evolved Universal Terrestrial Radio Access Network (EUTRAN) protocol, including, for example, physical layer (PHY) elements, medium access control (MAC) elements, radio link control (RLC) elements, packet data convergence protocol (PDCP) elements, and/or radio resource control (RRC) elements. The central processing unit (CPU) 204e of the baseband circuitry 204 may be configured to execute elements of the protocol stack for signaling at the PHY, MAC, RLC, PDCP, and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio digital signal processors (DSPs) 204f. The audio DSP(s) 204f may include elements for compression/decompression and echo cancellation, and in other embodiments may include other suitable processing elements. In some embodiments, the components of the baseband circuitry may be appropriately combined in a single chip, a single chipset, or arranged on the same circuit board. In some embodiments, some or all of the components of the baseband circuitry 204 and the application circuitry 202 may be implemented together (e.g., on a system-on-chip (SOC)).

In some embodiments, baseband circuitry 204 can provide communications compatible with one or more radio technologies. For example, in some embodiments, baseband circuitry 204 can support communications with the Evolved Universal Terrestrial Radio Access Network (EUTRAN) and/or other wireless metropolitan area networks (WMANs), wireless local area networks (WLANs), and wireless personal area networks (WPANs). Embodiments in which baseband circuitry 204 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

The RF circuitry 206 can enable communication with a wireless network through a non-solid medium using modulated electromagnetic radiation. In various embodiments, the RF circuitry 206 can include switches, filters, amplifiers, etc. to facilitate communication with the wireless network. The RF circuitry 206 can include a receive signal path that can include circuitry for down-converting RF signals received from the FEM circuitry 208 and providing baseband signals to the baseband circuitry 204. The RF circuitry 206 can also include a transmit signal path that can include circuitry for up-converting baseband signals provided by the baseband circuitry 204 and providing an RF output signal to the FEM circuitry 208 for transmission.

In some embodiments, RF circuitry 206 may include a receive signal path and a transmit signal path. The receive signal path of RF circuitry 206 may include mixer circuitry 206a, amplifier circuitry 206b, and filter circuitry 206c. The transmit signal path of RF circuitry 206 may include filter circuitry 206c and mixer circuitry 206a. RF circuitry 206 may also include synthesizer circuitry 206d to synthesize frequencies for use by mixer circuitry 206a in the receive and transmit signal paths. In some embodiments, mixer circuitry 206a in the receive signal path may be configured to down-convert the RF signal received from FEM circuitry 208 based on the synthesized frequency provided by synthesizer circuitry 206d. Amplifier circuitry 206b may be configured to amplify the down-converted signal, and filter circuitry 206c may be a low-pass filter (LPF) or a band-pass filter (BPF) configured to remove unwanted signals from the down-converted signal to generate an output baseband signal. The output baseband signal may be provided to baseband circuitry 204 for further processing. In some embodiments, the output baseband signal can be a zero-frequency baseband signal, but this is not required. In some embodiments, the mixer circuit 206a of the receive signal path can include a passive mixer, but the scope of the embodiments is not limited in this respect. In some embodiments, the mixer circuit 206a of the transmit signal path can be configured to up-convert the input baseband signal based on the synthesized frequency provided by the synthesizer circuit 206d to generate an RF output signal for the FEM circuit 208. The baseband signal can be provided by the baseband circuit 204 and can be filtered by the filter circuit 206c. The filter circuit 206c can include a low-pass filter (LPF), but the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuit 206a of the receive signal path and the mixer circuit 206a of the transmit signal path may include two or more mixers and may be arranged for quadrature down-conversion and/or up-conversion, respectively. In some embodiments, the mixer circuit 206a of the receive signal path and the mixer circuit 206a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuit 206a of the receive signal path and the mixer circuit 206a of the transmit signal path may be arranged for direct down-conversion and/or direct up-conversion, respectively. In some embodiments, the mixer circuit 206a of the receive signal path and the mixer circuit 206a of the transmit signal path may be configured for superheterodyne operation.

In some embodiments, the output baseband signal and the input baseband signal may be analog baseband signals, but the scope of the embodiments is not limited in this respect. In some alternative embodiments, the output baseband signal and the input baseband signal may be digital baseband signals. In these alternative embodiments, the RF circuit 206 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuits, and the baseband circuit 204 may include a digital baseband interface to communicate with the RF circuit 206. In some dual-mode embodiments, a separate radio IC circuit may be provided for each spectrum to process the signals, but the scope of the embodiments is not limited in this respect.

In some embodiments, synthesizer circuit 206d can be a fractional N type synthesizer or a fractional N/N+1 type synthesizer, but the scope of the embodiments is not limited in this respect, as other types of frequency synthesizers may also be suitable. For example, synthesizer circuit 206d can be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase-locked loop with a frequency divider. Synthesizer circuit 206d can be configured to synthesize an output frequency for use by mixer circuit 206a of RF circuit 206 based on a frequency input and a frequency divider control input. In some embodiments, synthesizer circuit 206d can be a fractional N/N+1 type synthesizer. In some embodiments, the frequency input can be provided by a voltage controlled oscillator (VCO), but this is not required. Depending on the desired output frequency, the frequency divider control input can be provided by either baseband circuit 204 or application processor 202. In some embodiments, the frequency divider control input (e.g., N) can be determined from a lookup table based on the channel indicated by application processor 202.

The synthesizer circuit 206d of the RF circuit 206 may include a frequency divider, a delay-locked loop (DLL), a multiplexer, and a phase accumulator. In some embodiments, the frequency divider may be a dual modulus divider (DMD), and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by N or N+1 (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded tunable delay elements, a phase detector, a charge pump, and a D-type flip-flop. In these embodiments, the delay elements may be configured to divide the VCO cycle into Nd equal phase packets, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay of the entire delay line is one VCO cycle.

In some embodiments, the synthesizer circuit 206 d can be configured to generate a carrier frequency as the output frequency, however, in other embodiments, the output frequency can be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with a quadrature generator and divider circuit to generate multiple signals at the carrier frequency with multiple different phases relative to each other. In some embodiments, the output frequency can be the LO frequency (f _LO ). In some embodiments, the RF circuit 206 can include an IQ/polarity converter.

FEM circuitry 208 may include a receive signal path that may include circuitry configured to operate on RF signals received from one or more of antennas 210A-210D, amplify the received signals, and provide the amplified versions of the received signals to RF circuitry 206 for further processing. FEM circuitry 208 may also include a transmit signal path that may include circuitry configured to amplify transmit signals provided by RF circuitry 206 for transmission by one or more of the one or more antennas 210A-210D.

In some embodiments, the FEM circuitry 208 may include a TX/RX switch to switch between transmit mode operation and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a low noise amplifier (LNA) to amplify a received RF signal and provide the amplified received RF signal as an output (e.g., to the RF circuitry 206). The transmit signal path of the FEM circuitry 208 may include a power amplifier (PA) to amplify an input RF signal (e.g., provided by the RF circuitry 206) and may also include one or more filters to generate an RF signal for subsequent transmission (e.g., by one or more of the one or more antennas 210). In some embodiments, the UE 200 may include additional components, such as memory/storage, a display, a camera, a sensor, or an input/output (I/O) interface.

FIG3 is a functional diagram of an evolved Node B (eNB) according to some embodiments. It should be noted that in some embodiments, eNB 300 may be a fixed, non-mobile device. eNB 300 may be suitable for use as eNB 104 shown in FIG1 . NB 300 may include physical layer circuitry 302 and a transceiver 305, one or both of which may enable the use of one or more antennas 301A-301B to transmit and receive signals to and from UE 200, other eNBs, other UEs, or other devices. As an example, physical layer circuitry 302 may perform various encoding and decoding functions, including forming baseband signals for transmission and decoding received signals. As another example, transceiver 305 may perform various transmission and reception functions, such as converting signals between baseband and radio frequency (RF) ranges. Thus, physical layer circuitry 302 and transceiver 305 may be separate components or may be part of a combined component. Furthermore, some of the functions described in connection with the transmission and reception of signals may be performed by any one, any, or all of the following: physical layer circuitry 302, transceiver 305, and other components or layers. The eNB 300 may also include medium access control (MAC) layer circuitry 304 for controlling access to the wireless medium. The eNB 300 may also include processing circuitry 306 and memory 308 arranged to perform the operations described herein. The eNB 300 may also include one or more interfaces 310 that enable communication with other components, including other eNBs 104 ( FIG. 1 ), components within the EPC 120 ( FIG. 1 ), or other network components. Additionally, the interfaces 310 may enable communication with other components that may not be shown in FIG. 1 , including components external to the network. The interfaces 310 may be wired, wireless, or a combination of both.

Antennas 210A-210D, 301A-301B may include one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmission of RF signals. In some multiple-input multiple-output (MIMO) embodiments, antennas 210A-210D, 301A-301B may be effectively separated to take advantage of possible spatial diversity and different channel characteristics.

In some embodiments, the UE 200 or eNB 300 may be a mobile device and may be a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capabilities, an internet tablet, a wireless phone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a wearable device such as a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), or other device that can wirelessly receive and/or transmit information. In some embodiments, the UE 200 or eNB 300 may be configured to operate according to 3GPP standards, but the scope of the embodiments is not limited in this respect. In some embodiments, the mobile device or other device may be configured to operate according to other protocols or standards, including IEEE 802.11 or other IEEE standards. In some embodiments, the UE 200, eNB 300, or other device may include one or more of the following: a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, a speaker, and other mobile device components. The display may be an LCD screen including a touch screen.

Although UE 200 and eNB 300 are each shown as having several separate functional elements, one or more of these functional elements may be combined and may be implemented by a combination of software-configured elements (e.g., a processing element including a digital signal processor (DSP)) and/or other hardware elements. For example, some elements may include one or more microprocessors, DSPs, field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), radio frequency integrated circuits (RFICs), and combinations of various hardware and logic circuits for performing at least the functions described herein. In some embodiments, a functional element may refer to one or more processes running on one or more processing elements.

Embodiments may be implemented in one or a combination of hardware, firmware, and software. Embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transient mechanism for storing information in a machine (e.g., computer) readable form. For example, a computer-readable storage device may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium, an optical storage medium, a flash memory device, and other storage devices and media. Some embodiments may include one or more processors and may be configured with instructions stored on a computer-readable storage device.

It should be noted that, in some embodiments, the apparatus used by UE 200 or eNB 300 may include various components of UE 200 and eNB 300 as shown in Figures 2-3. Therefore, the techniques and operations described herein involving UE 200 (or 102) may be applicable to the apparatus of the UE. In addition, the techniques and operations described herein involving eNB 300 (or 104) may be applicable to the apparatus of the eNB.

FIG4 illustrates an example of multi-beam transmission according to some embodiments. Although the example scenarios 400 and 450 shown in FIG4 may illustrate some aspects of the technology disclosed herein, it will be understood that the embodiments are not limited to the example scenarios 400 and 450. The embodiments are not limited to the number or type of components shown in FIG4, nor are they limited to the number or arrangement of transmit beams shown in FIG4.

In example scenario 400, eNB 104 can transmit signals on multiple beams 405-420, any one or all of which can be received at UE 102. It should be noted that the number of beams or transmission angles shown are not limiting. Because beams 405-420 can be directional, the transmitted energy from beams 405-420 can be focused in the directions shown. Therefore, in some situations, due to the relative position of UE 102, UE 102 may not necessarily receive a significant amount of energy from beams 405 and 410.

As shown, UE 102 can receive a significant amount of energy from beams 415 and 420. As an example, beams 405-420 can be transmitted using different reference signals, and UE 102 can determine channel state information (CSI) feedback or other information for beams 415 and 420. In some embodiments, each of beams 405-420 is configured as a CSI reference signal (CSI-RS). In a related embodiment, the CSI-RS signal is part of a discovery reference signaling (DRS) configuration. The DRS configuration can be used to inform UE 102 of the physical resources (e.g., subframes, subcarriers) on which the CSI-RS signal will be found. In a related embodiment, UE 102 is also informed of any scrambling sequence that will be applied to the CSI-RS.

In some embodiments, up to two MIMO layers can be transmitted within each beam using different polarizations. More than two MIMO layers can be transmitted using multiple beams. In a related embodiment, the UE is configured to discover available beams and report those discovered beams to the eNB using appropriate reporting messaging before performing MIMO data transmission. Based on the reporting messaging, the eNB 104 can determine the appropriate beam direction for the MIMO layer to be used for data communication with the UE 102. In various embodiments, there may be up to two, four, eight, sixteen, thirty-two, or more MIMO layers, depending on the number of MIMO layers supported by the eNB 104 and the UE 102. The number of MIMO layers that can actually be used in a given scenario will depend on the quality of the signaling received at the UE 102 and the availability of reflected beams arriving at the UE 102 at different angles so that the UE 102 can distinguish between the data carried on different beams.

In example scenario 450, UE 102 may determine angles or other information (e.g., CSI feedback, channel quality indicator (CQI), or other) for beams 465 and 470. UE 102 may also determine such information when being received at other angles (e.g., beams 475 and 480 as shown). Beams 475 and 480 are distinguished using a dashed configuration to indicate that they may not necessarily be transmitted at these angles, but UE 102 may use techniques such as receive beamforming to determine the beam directions of beams 475 and 480 as receive directions. This may occur, for example, when a transmit beam reflects off an object near UE 102 and arrives at UE 102 according to its reflection angle rather than its incident angle.

In some embodiments, UE 102 may transmit one or more channel state information (CSI) messages along with the report messaging to eNB 104. However, embodiments are not limited to dedicated CSI messaging, as UE 102 may include relevant reporting information in control messages or other types of messages that may or may not be dedicated to the transmission of CSI-type information.

As an example, a first signal received from a first eNB 104 may include a first directional beam based at least in part on a first CSI-RS signal and a second directional beam based at least in part on a second CSI-RS signal. UE 102 may determine a rank indicator (RI) for the first CSI-RS and an RI for the second CSI-RS, and may send both RIs in a CSI message. In addition, UE 102 may determine one or more RIs for the second signal, and in some cases may also include them in the CSI message. In some embodiments, UE 102 may also determine a CQI, a precoding matrix indicator (PMI), a reception angle, or other information for one or both of the first signal and the second signal. Such information may be included in one or more CSI messages together with the one or more RIs. In some embodiments, UE 102 uses the CSI-RS signal to perform reference signal received power (RSRP) measurement, received signal strength indication (RSSI) measurement, reference signal received quality (RSRQ) measurement, or some combination thereof.

RSRP provides information about the signal power from a specific cell while excluding noise and interference from other cells. The RSRP level of the available signal typically ranges from about -70dBm near the LTE cell site to -125dBm at the cell edge. RSRP is defined as the average power of the resource elements (REs) carrying the cell-specific reference signal (RS) over the entire bandwidth, i.e., RSRP is measured only in symbols carrying RS. For RSRP, the UE measures the power of multiple resource elements used to send the reference signal and takes the average value. The reporting range of RSRP supported by LTE signaling is currently defined as -44…-140dBm.

RSRQ provides link quality, which also takes into account RSSI (Received Signal Strength Indicator) and the number of resource blocks used (N), and is defined as RSRQ = (N*RSRP)/RSSI, where RSRP and RSSI are measured over the same bandwidth. RSRQ can also be seen as an SINR-type measurement, and it indicates the quality of the received reference signal (including the impact of interference). The RSRQ measurement includes the impact of interference in the RSSI. The RSRQ measurement also provides information about the channel load, which is particularly important for inter-frequency handover or cell reselection, where RSRP information is often not sufficient to make a reliable decision. The interference level is included in the RSSI measurement, which contains information about the observed average total received power, for example, in OFDM symbols that contain the reference symbol for antenna port 0 in the measurement bandwidth across N resource blocks (i.e., OFDM symbols 0 and 4 in the time slot). The total received power of the RSSI includes power from co-channel serving and non-serving interfering cells, adjacent channel interference, thermal noise, etc.

The LTE specification provides the flexibility to use RSRP, RSRQ, or both to assist in handover decisions. RSRP and RSRQ must be measured over the same bandwidth (either narrowband with N = 62 subcarriers (6 resource blocks) or wideband with N = full bandwidth (up to 100 resource blocks/20 MHz)). RRM measurements convey power information for both the target cell and the interfering cell.

Some aspects of the embodiments relate to extending RRM measurements to transmit MIMO-related information and IRC (Interference Rejection Capability)-related information for different cells to the eNB. For example, the MIMO-related information can be used to identify the size of the serving channel and estimate (e.g., roughly estimate) the expected number of layers that can be provided to the UE, such as after an inter-frequency handover. Similarly, the eNB can use the IRC-related information to estimate the signal quality after interference suppression at the UE receiver (e.g., also after an inter-frequency handover).

According to some embodiments, a new set of RRM measurements is defined to convey information about the spatial structure of serving and interfering signals taking into account multiple antennas at the UE and/or eNB. In some embodiments, RSRP and RSRQ definitions are enhanced to include measurement and reporting of multiple values for each target cell eNB.

FIG5 is a diagram illustrating a MIMO transmission scenario using an eNB and a UE, each with multiple antennas, according to some embodiments. As shown, eNB 502 has multiple antennas that can be used for various groups and with various signal modifications for each group, effectively generating multiple antenna ports P1-P4. In various embodiments within the framework of the illustrated example, each antenna port P1-P4 can be defined for one, two, three, or four antennas. Each antenna port P1-P4 can correspond to a different transmission signal direction. Using different antenna ports, eNB 502 can transmit multiple layers using codebook-based or non-codebook-based precoding techniques. According to some embodiments, antenna port-specific CSI-RS signals are transmitted via the corresponding antenna port. In other embodiments, more or fewer antenna ports are available at the eNB than the four shown in FIG5 .

On the UE side, multiple receive antennas are present. As shown in the example of Figure 5, there are four receive antennas A1-A4. Multiple receive antennas can be selectively used to generate receive beamforming. Receive beamforming can be advantageously used to increase receive antenna gain in the direction (or directions) of receiving the desired signal and to suppress interference from neighboring cells, assuming, of course, that the interference is received in a different direction from the desired signal.

According to some embodiments, the UE may be configured to perform multiple RRM measurements for different spatial transmit/receive configurations. In some embodiments, for example, the multiple reported values may correspond to different eigenvalues of a variance matrix measured using reference signals received on multiple antennas at the UE receiver.

More specifically, enhanced RSRP measurements can be performed where the UE can be configured with reference signals for one, two, or more antenna ports ( _Np≥1 ) of the eNB. In this example, the reference signal for each antenna port can be based on a non-zero power CSI-RS (NZP CSI-RS) signal.

Based on the NZP CSI-RS configuration, the UE can perform RRP measurements for each receive antenna and reference signal transmit antenna port pair of the eNB. The measurements can be stored in a data structure such as an N _rx × N _p matrix, where N _rx is the number of receive antennas and N _p is the number of transmit ports used by the eNB. For example, in the case of four antenna ports at the eNB and four receive antennas at the UE, as shown in the example of Figure 5, the complete set of measurements can be stored as a matrix R as shown below:

Wherein, Px:Ay represents the RRM value measured for each resource element (RE) and for each corresponding antenna port receiving antenna pairing.

The set of measured enhanced RSRPs for a given cell is then calculated as a set of characteristic values, such as:

eRSRP = eigval{E(R·R ^H )},

where the eigval(A) operation computes the eigenvalues of the square matrix A, and E(·) is a function averaged across reference signal resource elements.

For example, the eigenvalues of a complex Hermitian matrix A of size N _rx ×N _rx can be obtained by performing eigenvector decomposition on the matrix A:

Where U is a unitary matrix of size N _rx ×N _rx containing the eigenvectors, and λ1, λ2, ..., λ _Nrx are the required N _rx real-valued eigenvalues. Here, the eigenvalues describe the dimensionality of the channel. The eigenvalues themselves represent the average measurement for each possible beam direction. In related embodiments, reporting these eigenvalues to the eNB provides spatial communication performance.

In related aspects, an enhanced RSSI measurement may be defined as eRSSI = eigval{E(r·r ^H )}, where r for each RE has a dimension of N _rx ×1 and represents a received signal measurement for all resource elements within a measurement bandwidth spanning all OFDM symbols (e.g., containing reference signals, or containing other communications) or a subset thereof, for all receive antennas of the UE.

The eRSRQ calculation may then be defined as the ratio of (N*eRSRP)/eRSSI. The number of RSRP, RSSI, and RSRQ measurements for each measured cell may be further limited to the minimum of ( _Nrx , _Np ), or _Np . In related embodiments, a subset of the measured RSRP, RSSI, and RSRQ values is reported by the UE to the eNB based on one or more predefined triggering conditions.

FIG6 is a flow chart illustrating an example process for enhanced RRM performed by a UE, according to some embodiments. At 602, the UE receives configuration information from an eNB regarding RRM reference signaling. This may include, for example, information related to CSI-RS signaling. At 604, the UE receives configuration information establishing a reporting mode, i.e., using enhanced measurements to provide reference signal reports that take into account spatial transmit/receive performance. At 606, for each of the UE's multiple antennas, the UE performs enhanced signal quality measurements on each reference signal received from its corresponding eNB antenna port. At 608, the UE calculates the enhanced measurements based on the reporting configuration established by the eNB.

Additional notes and examples:

Example 1 is an apparatus of a user equipment (UE), the apparatus comprising a transceiver circuit and a processing circuit. The processing circuit: controls the transceiver circuit to receive a reference signal from a first evolved Node B (eNB) via multiple receive antennas of the UE, the reference signal being associated with at least one antenna port of the first eNB, the corresponding reference signal being transmitted through the at least one antenna port; performs received signal measurement on at least a portion of a plurality of combined grouped reference signals for at least one antenna port of the eNB and a receive antenna of the UE to generate an enhanced received signal quality (eRSQ) measurement, the eRSQ measurement representing spatial characteristics of different channels corresponding to the reference signal received by the UE; and controls the transceiver circuit to send a report to the first eNB based on the eRSQ measurement, the report indicating spatial multiplexing layer availability of the corresponding channel between the UE and the first eNB.

In Example 2, the subject matter of Example 1 can optionally include, wherein the reference signal comprises a channel state information reference signal (CSI-RS).

In Example 3, the subject matter of any one or more of Examples 1-2 optionally includes, wherein the reference signal includes channel state information reference signaling (CSI-RS), the CSI-RS includes multiple CSI-RS signals, each CSI-RS signal corresponding to an antenna port of the first eNB.

In Example 4, the subject matter of any one or more of Examples 1-3 may optionally include, wherein the plurality of combined groups are pairings of eNB antenna ports and UE receive antennas.

In Example 5, the subject matter of any one or more of Examples 1-4 may optionally include, wherein the eRSQ measurement represents spatial channel characteristics of a plurality of different multiple-input/multiple-output (MIMO) layers.

In Example 6, the subject matter of any one or more of Examples 1-5 may optionally include, wherein the processing circuit further: controls the transceiver circuit to receive configuration information from the first eNB, wherein the configuration information instructs the UE to perform eRSQ measurement and reporting.

In Example 7, the subject matter of any one or more of Examples 1-6 may optionally include, wherein the processing circuit further: controls the transceiver circuit to receive configuration information from the first eNB, wherein the configuration information includes an indication, and the processing circuit is to determine the number of antenna ports of the first eNB based on the indication.

In Example 8, the subject matter of any one or more of Examples 1-7 may optionally include, wherein the report comprises a radio resource management (RRM) message.

In Example 9, the subject matter of any one or more of Examples 1-8 may optionally include, wherein the eRSQ measurement is based on a calculated aggregation of received power measurements over a plurality of spatial channels.

In Example 10, the subject matter of any one or more of Examples 1-9 may optionally include, wherein the eRSQ measurement is based on a calculated aggregation of ratios of received signal power measurements and received signal strength measurements over the plurality of spatial channels.

In Example 11, the subject matter of any one or more of Examples 1-10 may optionally include, wherein the processing circuit further: when the UE is connected to the first eNB, controls the transceiver circuit to receive, via multiple receive antennas, a neighboring cell signal transmitted from the second eNB via at least one antenna port of the second eNB; and performs interference received signal measurement on at least a portion of the neighboring cell signals for the multiple UE receive antennas to generate an interference profile, the interference profile representing spatial characteristics of the interference signal originating from the second eNB received by the UE.

In Example 12, the subject matter of Example 11 may optionally include, wherein the interference profile is reported to the eNB.

In Example 13, the subject matter of any one or more of Examples 1-12 may optionally include, wherein the received signal measurement is defined for 6 resource blocks.

In Example 14, the subject matter of any one or more of Examples 1-13 may optionally include, wherein the received signal measurement is defined for one hundred resource blocks.

In Example 15, the subject matter of any one or more of Examples 1-14 may optionally include, wherein the plurality of receive antennas includes two receive antennas.

In Example 16, the subject matter of any one or more of Examples 1-15 may optionally include, wherein the plurality of receive antennas includes four receive antennas.

In Example 17, the subject matter of any one or more of Examples 1-16 may optionally include, wherein the reference signaling includes a non-zero power channel state information reference signal (NZ CSI-RS).

In Example 18, the subject matter of any one or more of Examples 1-17 may optionally include, wherein the received signal measurements are stored as an N _rx ×N _p matrix R, where N _rx is the number of receive antennas and N _p is the number of antenna ports of the first eNB for each resource element (RE) of the first eNB.

In Example 19, the subject matter of Example 18 can optionally include, wherein the reporting based on the eRSRQ measurement is based on a first set of eigenvalues defined as eRSRP=eigval{E(R· ^RH )}, where eigval{} corresponds to an eigenvalue computation of a square matrix, E is an averaging function, and ^RH is the conjugate transpose of the matrix R.

In Example 20, the subject matter of Example 19 may optionally include, wherein the reporting based on the eRSRQ measurement is further based on a second set of eigenvalues defined as eRSSI=eigval{E(r·r ^H )}, where eigval{} corresponds to eigenvalues of a square matrix, E is an averaging function, and r ^H is the conjugate transpose of a vector r, where vector r includes received signal measurements for all receive antennas of the UE for all resource elements.

In Example 21, the subject matter of Example 20 optionally includes, wherein the reporting based on the eRSRQ measurement is further based on a ratio defined as N·eRSRP/eRSSI, where N is the number of resource blocks, and the number of eRSRP and eRSSI values used for the eRSRQ operation can be determined based on the minimum of N _rx and N _p .

Example 22 is a computer-readable medium comprising instructions that, when executed on a processing circuit of a user equipment (UE), cause the UE to: receive a reference signal from a first evolved Node B (eNB) via multiple receive antennas of the UE, the reference signal being associated with at least one antenna port of the first eNB, the corresponding reference signal being transmitted through the at least one antenna port; perform receive signal measurements on at least a portion of a plurality of combined grouped reference signals for at least one antenna port of the eNB and a receive antenna of the UE to generate enhanced receive signal quality (eRSQ) measurements, the eRSQ measurements representing spatial characteristics of different channels corresponding to the reference signals received by the UE; and send a report to the first eNB based on the eRSQ measurements, the report indicating spatial multiplexing layer availability of the corresponding channels between the UE and the first eNB.

In Example 23, the subject matter of Example 22 may optionally include, wherein the reference signal comprises a channel state information reference signal (CSI-RS).

In Example 24, the subject matter of any one or more of Examples 22-23 optionally includes, wherein the reference signal includes channel state information reference signaling (CSI-RS), the CSI-RS includes a plurality of CSI-RS signals, each CSI-RS signal corresponding to an antenna port of the first eNB.

In Example 25, the subject matter of any one or more of Examples 22-24 may optionally include, wherein the plurality of combined groups are pairings of eNB antenna ports and UE receive antennas.

In Example 26, the subject matter of any one or more of Examples 22-25 may optionally include, wherein the eRSQ measurement represents spatial channel characteristics of a plurality of different multiple-input/multiple-output (MIMO) layers.

In Example 27, the subject matter of any one or more of Examples 22-26 may optionally include, wherein the instructions further cause the UE to: receive configuration information from the first eNB, wherein the configuration information instructs the UE to perform eRSQ measurement and reporting.

In Example 28, the subject matter of any one or more of Examples 22-27 may optionally include, wherein the instructions further cause the UE to: receive configuration information from the first eNB, wherein the configuration information includes an indication based on which the processing circuit is to determine the number of antenna ports of the first eNB.

In Example 29, the subject matter of any one or more of Examples 22-28 may optionally include, wherein the report comprises a radio resource management (RRM) message.

In Example 30, the subject matter of any one or more of Examples 22-29 may optionally include, wherein the eRSQ measurement is based on a calculated aggregation of received power measurements over a plurality of spatial channels.

In Example 31, the subject matter of any one or more of Examples 22-30 may optionally include, wherein the eRSQ measurement is based on a calculated aggregation of ratios of received signal power measurements and received signal strength measurements over the plurality of spatial channels.

In Example 32, the subject matter of any one or more of Examples 22-31 optionally includes, wherein the instructions further cause the UE to: when the UE is connected to the first eNB, receive, via multiple receive antennas, a neighboring cell signal transmitted from the second eNB via at least one antenna port of the second eNB; and perform interference received signal measurement on at least a portion of the neighboring cell signals for the multiple UE receive antennas to generate an interference profile, the interference profile representing spatial characteristics of the interference signal originating from the second eNB received by the UE.

In Example 33, the subject matter of Example 32 may optionally include, wherein the interference profile is reported to the eNB.

In Example 34, the subject matter of any one or more of Examples 22-33 may optionally include, wherein the received signal measurement is defined for 6 resource blocks.

In Example 35, the subject matter of any one or more of Examples 22-34 may optionally include, wherein the received signal measurement is defined for one hundred resource blocks.

In Example 36, the subject matter of any one or more of Examples 22-35 may optionally include, wherein the plurality of receive antennas includes two receive antennas.

In Example 37, the subject matter of any one or more of Examples 22-36 may optionally include, wherein the plurality of receive antennas includes four receive antennas.

In Example 38, the subject matter of any one or more of Examples 22-37 may optionally include, wherein the reference signaling includes a non-zero power channel state information reference signal (NZ CSI-RS).

In Example 39, the subject matter of any one or more of Examples 22-38 may optionally include, wherein the received signal measurements are stored as an N _rx ×N _p matrix R, where N _rx is the number of receive antennas and N _p is the number of antenna ports of the first eNB for each resource element (RE) of the first eNB.

In Example 40, the subject matter of Example 39 may optionally include, wherein the reporting based on the eRSRQ measurement is based on a first set of eigenvalues defined as eRSRP=eigval{E(R· ^RH )}, where eigval{} corresponds to an eigenvalue computation of a square matrix, E is an averaging function, and ^RH is the conjugate transpose of the matrix R.

In Example 41, the subject matter of Example 40 may optionally include, wherein the reporting based on the eRSRQ measurement is further based on a second set of eigenvalues defined as eRSSI=eigval{E(r·r ^H )}, where eigval{} corresponds to eigenvalues of a square matrix, E is an averaging function, and r ^H is the conjugate transpose of a vector r, where vector r includes received signal measurements for all receive antennas of the UE for all resource elements.

In Example 42, the subject matter of Example 41 optionally includes, wherein the reporting based on the eRSRQ measurement is further based on a ratio defined as N·eRSRP/eRSSI, where N is the number of resource blocks, and the number of eRSRP and eRSSI values used for the eRSRQ operation can be determined based on the minimum of N _rx and N _p .

Example 43 is an apparatus of a user equipment (UE), the apparatus comprising a transceiver circuit and a processing circuit. The processing circuit: controls the transceiver circuit to connect to a first evolved Node B (eNB) via multiple receive antennas of the UE; when the UE is connected to the first eNB, controls the transceiver circuit to receive neighboring cell signals from a second eNB via the multiple receive antennas; performs interference reception signal measurement on at least a portion of the neighboring cell signals for the multiple UE receive antennas to generate an interference profile, the interference profile representing spatial characteristics of interference signals originating from the second eNB received by the UE; and controls the transceiver circuit to send a report to the first eNB based on the interference profile.

In Example 44, the subject matter of Example 43 optionally includes, wherein the interference profile is represented as a calculated aggregation of received power measurements on multiple resource elements (REs) and orthogonal frequency division multiplexing (OFDM) symbols corresponding to respective ones of the multiple receive antennas.

In Example 45, the subject matter of any one or more of Examples 43-44 optionally includes, wherein the interference received signal measurement is an enhanced received signal strength indication (eRSSI) represented as an N _rx -dimensional vector, where N _rx is the number of receive antennas at the UE, the vector including signal strength measurements corresponding to each antenna and aggregated over multiple resource blocks.

In Example 46, the subject matter of any one or more of Examples 43-45 may optionally include, wherein the interference received signal measurement is defined for 6 resource blocks.

In Example 47, the subject matter of any one or more of Examples 43-46 may optionally include, wherein the interference received signal measurement is defined for one hundred resource blocks.

In Example 48, the subject matter of any one or more of Examples 43-47 may optionally include, wherein the processing circuit further: controls the transceiver circuit to receive configuration information from the first eNB, wherein the configuration information instructs the UE to perform interference received signal measurement.

In Example 49, the subject matter of any one or more of Examples 43-48 may optionally include, wherein the plurality of receive antennas includes two receive antennas.

In Example 50, the subject matter of any one or more of Examples 43-49 may optionally include, wherein the plurality of receive antennas includes at least four receive antennas.

The above detailed description includes references to the accompanying drawings that form a part of the detailed description. The accompanying drawings show, by way of illustration, specific embodiments that may be practiced. These embodiments are also referred to herein as "examples." Such examples may include elements in addition to those shown or described. However, examples that include the elements shown or described are also contemplated. Moreover, examples using any combination or arrangement of those elements shown or described (or one or more aspects thereof) are also contemplated, regardless of whether those elements are shown or described herein with respect to a particular example (or one or more aspects thereof) or with respect to other examples (or one or more aspects thereof).

The publications, patents, and patent documents mentioned in this document are incorporated herein by reference in their entirety, as if each were incorporated herein by reference. In the event of inconsistent usages between this document and a document incorporated by reference, the usage in the incorporated reference(s) supplements this document; for conflicting inconsistencies, the usage in this document controls.

In this document, the terms "a" or "an" as commonly used in patent literature are used to include one or more than one, independent of any other instance or use of "at least one" or "one or more". In this document, the term "or" is used to refer to a non-exclusive or, so that unless otherwise specified, "A or B" includes "A but not B", "B but not A", and "A and B". In this document, the terms "including" and "in which" are used as the plain English equivalents of the corresponding terms "comprising" and "wherein". In addition, in the appended claims, the terms "including" and "comprising" are open-ended, that is, a system, device, article, or process that includes elements other than those listed after such a term in a claim is still considered to fall within the scope of the claim. In addition, in the appended claims, the terms "first", "second", and "third", etc. are used merely as labels and are not intended to indicate a numerical order of their objects.

The above description is intended to be illustrative and not restrictive. For example, the examples described above (or one or more aspects thereof) may be used in combination with other examples. For example, a person of ordinary skill in the art may use other embodiments after reviewing the above description. The abstract is intended to allow the reader to quickly determine the essence of the present disclosure. It should be understood that the abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Moreover, in the above detailed description, various features may be combined together to simplify the disclosure. However, the claims may not set forth every feature disclosed herein, as the embodiments may have a subset of the features. In addition, the embodiments may include fewer features than those disclosed in the specific examples. Therefore, the appended claims are incorporated into the detailed description, with the claims independently serving as separate embodiments. The scope of the embodiments disclosed herein will be determined with reference to the appended claims and the full scope of equivalents to these claims.

Claims (32)

1. An apparatus for a user equipment (UE), the apparatus comprising a transceiver circuit and a processing circuit, the processing circuit being: The transceiver circuitry is controlled to receive reference signals from a first evolved Node B eNB via multiple receive antennas of the UE. The reference signals are associated with at least one antenna port of the first eNB, and the corresponding reference signals are transmitted through the at least one antenna port. Received signal measurements are performed on at least a portion of a plurality of combined packets of reference signals for at least one antenna port of the eNB and the receive antenna of the UE to generate enhanced received signal quality (eRSQ) measurements, the eRSQ measurements representing the spatial characteristics of different channels corresponding to the reference signals received by the UE; and The transceiver circuitry is controlled to send a report to the first eNB based on the eRSQ measurement, the report indicating the spatial multiplexing layer availability of the corresponding channel between the UE and the first eNB. The received signal measurement is stored as an N _rx × N _p matrix R, where N _rx is the number of the receiving antennas and N _p is the number of antenna ports of the first eNB for each resource element RE of the first eNB. The report based on the eRSQ measurement is based on a first set of eigenvalues defined as eRSRP = eigval{E(R· ^RH )}, where eigval{} corresponds to the eigenvalue calculation for a square matrix, E is the averaging function, and ^RH is the conjugate transpose of matrix R; and The report based on the eRSQ measurement is also based on a second set of eigenvalues defined as eRSSI = eigval{E(r· ^rH )}, where eigval{} corresponds to the eigenvalues for the matrix, E is the averaging function, and ^rH is the conjugate transpose of vector r, where vector r includes received signal measurements for all resource elements and for all receiving antennas of the UE. 2. The apparatus of claim 1, wherein the reference signal includes a channel state information reference signal (CSI-RS), the CSI-RS including a plurality of CSI-RS signals, each CSI-RS signal corresponding to an antenna port of the first eNB. 3. The apparatus of claim 1, wherein the eRSQ measurement represents the spatial channel characteristics of multiple different multiple-input/multiple-output MIMO layers. 4. The apparatus of claim 1, wherein the eRSQ measurement is based on a calculated aggregation of received power measurements on multiple spatial channels. 5. The apparatus of claim 1, wherein the eRSQ measurement is based on a calculated aggregation of the ratios of received signal power measurements and received signal strength measurements across a plurality of spatial channels. 6. The apparatus of claim 1, wherein the processing circuit further comprises: When the UE is connected to the first eNB, it controls the transceiver circuit to receive neighboring cell signals transmitted from the second eNB via at least one antenna port of the second eNB through the plurality of receiving antennas; Interference reception signal measurements are performed on at least a portion of the neighboring cell signals for multiple UE receive antennas to generate an interference profile, the interference profile representing the spatial characteristics of interference signals originating from the second eNB received by the UE. 7. The apparatus of claim 6, wherein the interference profile is reported to the first eNB. 8. The apparatus of claim 1, wherein the reference signal includes a non-zero power channel state information reference signal (NZ CSI-RS). 9. The apparatus of claim 1, wherein the report based on the eRSQ measurement is further based on a ratio defined as N·eRSRP/eRSSI, where N is the number of resource blocks, and the number of eRSRP and eRSSI values used for the eRSQ calculation can be determined from the minimum of _Nrx and _Np . 10. A computer-readable medium comprising a computer program, said computer program, when executed on the processing circuitry of a user equipment (UE), causing the UE to: The UE receives a reference signal from the first evolved Node B eNB via multiple receive antennas. The reference signal is associated with at least one antenna port of the first eNB, and the corresponding reference signal is transmitted through the at least one antenna port. Received signal measurements are performed on at least a portion of a plurality of combined packets of reference signals for at least one antenna port of the eNB and the receive antenna of the UE to generate enhanced received signal quality (eRSQ) measurements, the eRSQ measurements representing the spatial characteristics of different channels corresponding to the reference signals received by the UE; and Based on the eRSQ measurement, a report is sent to the first eNB, the report indicating the spatial multiplexing layer availability of the corresponding channel between the UE and the first eNB. The received signal measurement is stored as an N _rx × N _p matrix R, where N _rx is the number of the receiving antennas and N _p is the number of antenna ports of the first eNB for each resource element RE of the first eNB. The report based on the eRSQ measurement is based on a first set of eigenvalues defined as eRSRP = eigval{E(R· ^RH )}, where eigval{} corresponds to the eigenvalue calculation for a square matrix, E is the averaging function, and ^RH is the conjugate transpose of matrix R; and The report based on the eRSQ measurement is also based on a second set of eigenvalues defined as eRSSI = eigval{E(r· ^rH )}, where eigval{} corresponds to the eigenvalues for the matrix, E is the averaging function, and ^rH is the conjugate transpose of vector r, where vector r includes received signal measurements for all resource elements and for all receiving antennas of the UE. 11. The computer-readable medium of claim 10, wherein the reference signal includes a channel state information reference signal (CSI-RS). 12. The computer-readable medium of claim 10, wherein the plurality of combined groups are a pairing of an eNB antenna port and a UE receiving antenna. 13. The computer-readable medium of claim 10, wherein the computer program further causes the UE to: The UE receives configuration information from the first eNB, wherein the configuration information instructs the UE to perform the eRSQ measurement and reporting. 14. The computer-readable medium of claim 10, wherein the computer program further causes the UE to: The processing circuit receives configuration information from the first eNB, wherein the configuration information includes an indication, and the processing circuit determines the number of antenna ports of the eNB based on the indication. 15. The computer-readable medium of claim 10, wherein the report comprises Radio Resource Management (RRM) messages. 16. The computer-readable medium of claim 10, wherein the eRSQ measurement is based on a calculated aggregation of received power measurements on a plurality of spatial channels. 17. The computer-readable medium of claim 10, wherein the eRSQ measurement is based on a calculated aggregation of the ratios of received signal power measurements and received signal strength measurements on a plurality of spatial channels. 18. The computer-readable medium of claim 10, wherein the computer program further causes the UE to: When the UE is connected to the first eNB, it receives neighboring cell signals transmitted from the second eNB via at least one antenna port of the second eNB through the plurality of receiving antennas; Interference reception signal measurements are performed on at least a portion of the neighboring cell signals for multiple UE receive antennas to generate an interference profile, the interference profile representing the spatial characteristics of interference signals originating from the second eNB received by the UE. 19. The computer-readable medium of claim 18, wherein the interference profile is reported to the first eNB. 20. The computer-readable medium of claim 10, wherein the report based on the eRSQ measurement is further based on a ratio defined as N·eRSRP/eRSSI, where N is the number of resource blocks, and the number of eRSRP and eRSSI values used for the eRSQ calculation can be determined from the minimum of _Nrx and _Np . 21. A method performed by a user equipment (UE), comprising: The UE receives a reference signal from the first evolved Node B eNB via multiple receive antennas. The reference signal is associated with at least one antenna port of the first eNB, and the corresponding reference signal is transmitted through the at least one antenna port. Received signal measurements are performed on at least a portion of a plurality of combined packets of reference signals for at least one antenna port of the eNB and the receive antenna of the UE to generate enhanced received signal quality (eRSQ) measurements, the eRSQ measurements representing the spatial characteristics of different channels corresponding to the reference signals received by the UE; and Based on the eRSQ measurement, a report is sent to the first eNB, the report indicating the spatial multiplexing layer availability of the corresponding channel between the UE and the first eNB. The received signal measurement is stored as an N _rx × N _p matrix R, where N _rx is the number of the receiving antennas and N _p is the number of antenna ports of the first eNB for each resource element RE of the first eNB. The report based on the eRSQ measurement is based on a first set of eigenvalues defined as eRSRP = eigval{E(R· ^RH )}, where eigval{} corresponds to the eigenvalue calculation for a square matrix, E is the averaging function, and ^RH is the conjugate transpose of matrix R; and The report based on the eRSQ measurement is also based on a second set of eigenvalues defined as eRSSI = eigval{E(r· ^rH )}, where eigval{} corresponds to the eigenvalues for the matrix, E is the averaging function, and ^rH is the conjugate transpose of vector r, where vector r includes received signal measurements for all resource elements and for all receiving antennas of the UE. 22. The method of claim 21, wherein the reference signal includes a channel state information reference signal (CSI-RS). 23. The method of claim 21, wherein the plurality of combined groups are pairings of eNB antenna ports and UE receive antennas. 24. The method of claim 21, further comprising: The UE receives configuration information from the first eNB, wherein the configuration information instructs the UE to perform the eRSQ measurement and reporting. 25. The method of claim 21, further comprising: Configuration information is received from the first eNB, wherein the configuration information includes an indication used to determine the number of antenna ports of the eNB. 26. The method of claim 21, wherein the report comprises a Radio Resource Management (RRM) message. 27. The method of claim 21, wherein the eRSQ measurement is based on a calculated aggregation of received power measurements on multiple spatial channels. 28. The method of claim 21, wherein the eRSQ measurement is based on a calculated aggregation of the ratios of received signal power measurements and received signal strength measurements across a plurality of spatial channels. 29. The method of claim 21, further comprising: When the UE is connected to the first eNB, it receives neighboring cell signals transmitted from the second eNB via at least one antenna port of the second eNB through the plurality of receiving antennas; Interference reception signal measurements are performed on at least a portion of the neighboring cell signals for multiple UE receive antennas to generate an interference profile, the interference profile representing the spatial characteristics of interference signals originating from the second eNB received by the UE. 30. The method of claim 29, wherein the interference profile is reported to the first eNB. 31. The method of claim 21, wherein the report based on the eRSQ measurement is further based on a ratio defined as N·eRSRP/eRSSI, where N is the number of resource blocks, and the number of eRSRP and eRSSI values used for the eRSQ calculation can be determined based on the minimum of _Nrx and _Np . 32. A user equipment (UE) device, comprising means for performing the method as claimed in any one of claims 21 to 31.