Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/20—Control channels or signalling for resource management
  • H04W72/23—Control channels or signalling for resource management in the downlink direction of a wireless link, i.e. towards a terminal
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/003—Arrangements for allocating sub-channels of the transmission path
  • H04L5/0032—Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
  • H04L5/0035—Resource allocation in a cooperative multipoint environment
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/003—Arrangements for allocating sub-channels of the transmission path
  • H04L5/0048—Allocation of pilot signals, i.e. of signals known to the receiver
  • H04L5/005—Allocation of pilot signals, i.e. of signals known to the receiver of common pilots, i.e. pilots destined for multiple users or terminals
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W24/00—Supervisory, monitoring or testing arrangements
  • H04W24/10—Scheduling measurement reports ; Arrangements for measurement reports
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/20—Control channels or signalling for resource management
  • H04W72/21—Control channels or signalling for resource management in the uplink direction of a wireless link, i.e. towards the network
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/50—Allocation or scheduling criteria for wireless resources
  • H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
  • H04W72/541—Allocation or scheduling criteria for wireless resources based on quality criteria using the level of interference
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/0001—Arrangements for dividing the transmission path
  • H04L5/0003—Two-dimensional division
  • H04L5/0005—Time-frequency
  • H04L5/0007—Time-frequency the frequencies being orthogonal, e.g. OFDM(A) or DMT
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W24/00—Supervisory, monitoring or testing arrangements
  • H04W24/08—Testing, supervising or monitoring using real traffic

Definitions

• the present disclosure relates to communication systems and to techniques for assigning interference measurement resources in wireless communication.
• Wireless communication networks are widely deployed to provide various communication content such as voice, video, packet data, messaging, broadcast, etc. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Examples of such multiple- access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.
• CDMA Code Division Multiple Access
• TDMA Time Division Multiple Access
• FDMA Frequency Division Multiple Access
• OFDMA Orthogonal FDMA
• SC-FDMA Single-Carrier FDMA
• a wireless communication network may include a number of base stations that can support communication for a number of mobile entities, such as, for example, user equipments (UEs).
• UE user equipments
• a UE may communicate with a base station via the downlink (DL) and uplink (UL).
• the DL (or forward link) refers to the communication link from the base station to the UE
• the UL (or reverse link) refers to the communication link from the UE to the base station.
• LTE Long Term Evolution
• GSM Global System for Mobile communications
• UMTS Universal Mobile Telecommunications System
• PHY physical layer
• a method of wireless communication includes receiving at least one identifier wherein the at least one identifier determines, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource, wherein the at least one interference measurement resource comprises a number of resource elements out of a set of resource elements.
• the method includes measuring interference based at least in part on the at least one interference measurement resource.
• a wireless communication apparatus includes at least one processor configured to (a) receive at least one identifier wherein the at least one identifier determines, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource, wherein the at least one interference measurement resource comprises a number of resource elements out of a set of resource elements, and (b) measure interference based at least in part on the at least one interference measurement resource.
• the wireless communication apparatus includes a memory coupled to the at least one processor for storing data.
• a wireless communication apparatus includes means for receiving at least one identifier wherein the at least one identifier determines, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource, wherein the at least one interference measurement resource comprises a number of resource elements out of a set of resource elements.
• the wireless communication apparatus includes means for measuring interference based at least in part on the at least one interference measurement resource.
• a computer program product includes a computer-readable medium including code for causing at least one computer to receive at least one identifier wherein the at least one identifier determines, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource, wherein the at least one interference measurement resource includes a number of resource elements out of a set of resource elements.
• the computer-readable medium includes code for causing the at least one computer to measure interference based at least in part on the at least one interference measurement resource.
• a method of wireless communication includes transmitting an identifier of a network entity to at least one mobile entity, the identifier determining, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource, wherein the at least one interference measurement resource comprises a number of resource elements out of a set of resource elements.
• the method includes receiving channel state information (CSI) reports from at least one mobile entity based on the at least one interference measurement resource.
• CSI channel state information
• a wireless communication apparatus includes at least one processor configured to (a) transmit an identifier of a network entity to at least one mobile entity, the identifier determining, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource, wherein the at least one interference measurement resource comprises a number of resource elements out of a set of resource elements, and (b) receive channel state information (CSI) reports from at least one mobile entity based on the at least one interference measurement resource.
• the wireless communication apparatus includes a memory coupled to the at least one processor for storing data.
• a wireless communication apparatus includes means for transmitting an identifier of a network entity to at least one mobile entity, the identifier determining, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource, wherein the at least one interference measurement resource comprises a number of resource elements out of a set of resource elements.
• the wireless communication apparatus includes means for receiving channel state information (CSI) reports from at least one mobile entity based on the at least one interference measurement resource.
• CSI channel state information
• a computer program product includes a computer-readable medium comprising code for causing at least one computer to transmit an identifier of a network entity to at least one mobile entity, the identifier determining, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource, wherein the at least one interference measurement resource comprises a number of resource elements out of a set of resource elements.
• the computer-readable medium includes code for causing the at least one computer to receive channel state information (CSI) reports from at least one mobile entity based on the at least one interference measurement resource.
• CSI channel state information
• FIG. 1 is a block diagram conceptually illustrating an example of a telecommunications system.
• FIG. 2 is a block diagram conceptually illustrating an example of a down link frame structure in a telecommunications system.
• FIG. 3 is a block diagram conceptually illustrating a design of a base station/eNB and a UE.
• FIGs. 4A-C illustrate resource element assignments using a two Stage process.
• FIGs. 5A-B illustrate resource element assignments for two cells.
• FIG. 5C illustrates possible overlap in resource element assignments for the two cells.
• FIGs. 5D-E illustrate different overlapping scenarios for resource element assignments for two cells.
• FIG. 6 illustrates an exemplary methodology for measuring interference resources.
• FIG. 7 illustrates an exemplary methodology for assigning interference measurement resources.
• FIG. 8 shows an embodiment of an apparatus for measuring interference resources, in accordance with the methodology of FIG. 6.
• FIG. 9 shows an embodiment of an apparatus for assigning interference measurement resources, in accordance with the methodology of FIG. 7.
• a CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc.
• UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA.
• cdma2000 covers IS-2000, IS-95 and IS-856 standards.
• a TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM).
• GSM Global System for Mobile Communications
• An OFDMA network may implement a radio technology such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.1 1 (Wi- Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc.
• E-UTRA Evolved UTRA
• UMB Ultra Mobile Broadband
• IEEE 802.1 1 Wi- Fi
• IEEE 802.16 WiMAX
• IEEE 802.20 Flash-OFDMA
• UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS).
• 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are new releases of UMTS that use E- UTRA.
• UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP).
• CDMA2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2).
• FIG. 1 shows a wireless communication network 100, which may be an LTE network.
• the wireless network 100 may include a number of eNBs 1 10 and other network entities.
• An eNB may be a station that communicates with the UEs and may also be referred to as a base station, a Node B, an access point, or other term.
• Each eNB 1 10a, 1 10b, 110c may provide communication coverage for a particular geographic area.
• the term "cell" can refer to a coverage area of an eNB and/or an eNB subsystem serving this coverage area, depending on the context in which the term is used.
• An eNB may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or other types of cell.
• a macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription.
• a pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription.
• a femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having association with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG), UEs for users in the home, etc.).
• CSG Closed Subscriber Group
• An eNB for a macro cell may be referred to as a macro eNB.
• An eNB for a pico cell may be referred to as a pico eNB.
• An eNB for a femto cell may be referred to as a femto eNB or a home eNB (FTNB).
• the eNBs 110a, 110b and 1 10c may be macro eNBs for the macro cells 102a, 102b and 102c, respectively.
• the eNB HOx may be a pico eNB for a pico cell 102x.
• the eNBs 1 lOy and 1 lOz may be femto eNBs for the femto cells 102y and 102z, respectively.
• An eNB may support one or multiple (e.g., three) cells.
• the wireless network 100 may also include relay stations HOr.
• a relay station is a station that receives a transmission of data and/or other information from an upstream station (e.g., an eNB or a UE) and sends a transmission of the data and/or other information to a downstream station (e.g., a UE or an eNB).
• a relay station may also be a UE that relays transmissions for other UEs. In the example shown in FIG.
• a relay station 1 1 may communicate with the eNB 1 10a and a UE 120r in order to facilitate communication between the eNB 1 10a and the UE 120r.
• a relay station may also be referred to as a relay eNB, a relay, etc.
• the wireless network 100 may be a heterogeneous network that includes eNBs of different types, e.g., macro eNBs, pico eNBs, femto eNBs, relays, etc. These different types of eNBs may have different transmit power levels, different coverage areas, and different impact on interference in the wireless network 100.
• macro eNBs may have a high transmit power level (e.g., 20 Watts) whereas pico eNBs, femto eNBs and relays may have a lower transmit power level (e.g., 1 Watt).
• the wireless network 100 may support synchronous or asynchronous operation.
• the eNBs may have similar frame timing, and transmissions from different eNBs may be approximately aligned in time.
• the eNBs may have different frame timing, and transmissions from different eNBs may not be aligned in time.
• the techniques described herein may be used for both synchronous and asynchronous operation.
• a network controller 130 may couple to a set of eNBs and provide coordination and control for these eNBs.
• the network controller 130 may communicate with the eNBs 1 10 via a backhaul.
• the eNBs 110 may also communicate with one another, e.g., directly or indirectly via wireless or wireline backhaul.
• the UEs 120 may be dispersed throughout the wireless network 100, and each UE may be stationary or mobile.
• a UE may also be referred to as a terminal, a mobile station, a subscriber unit, a station, etc.
• a UE may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, or other mobile entities.
• PDA personal digital assistant
• WLL wireless local loop
• a UE may be able to communicate with macro eNBs, pico eNBs, femto eNBs, relays, or other network entities.
• LTE utilizes orthogonal frequency division multiplexing (OFDM) on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink.
• OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, bins, etc. Each subcarrier may be modulated with data.
• modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM.
• the spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system bandwidth.
• K may be equal to 128, 256, 512, 1024 or 2048 for system bandwidth of 1.25, 2.5, 5, 10 or 20 megahertz (MHz), respectively.
• the system bandwidth may also be partitioned into subbands. For example, a subband may cover 1.08 MHz, and there may be 1, 2, 4, 8 or 16 subbands for system bandwidth of 1.25, 2.5, 5, 10 or 20 MHz, respectively.
• FIG. 2 shows a down link frame structure used in LTE.
• the transmission timeline for the downlink may be partitioned into units of radio frames.
• Each radio frame for example, frame 202, may have a predetermined duration (e.g., 10 milliseconds (ms)) and may be partitioned into 10 subframes 204 with indices of 0 through 9.
• Each subframe for example 'Subframe 0' 206, may include two slots, for example, 'Slot 0' 208 and 'Slot 210.
• Each radio frame may thus include 20 slots with indices of 0 through 19.
• Each slot may include L symbol periods, e.g., 7 symbol periods 212 for a normal cyclic prefix (CP), as shown in FIG.
• CP normal cyclic prefix
• the normal CP and extended CP may be referred to herein as different CP types.
• the 2L symbol periods in each subframe may be assigned indices of 0 through 2L-1.
• the available time frequency resources may be partitioned into resource blocks. Each resource block may cover N subcarriers (e.g., 12 subcarriers) in one slot.
• an eNB may send a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) for each cell in the eNB.
• the primary and secondary synchronization signals may be sent in symbol periods 6 and 5, respectively, in each of subframes 0 and 5 of each radio frame with the normal cyclic prefix, as shown in FIG. 2.
• the synchronization signals may be used by UEs for cell detection and acquisition.
• the eNB may send a Physical Broadcast Channel (PBCH) in symbol periods 0 to 3 in slot 1 of subframe 0.
• PBCH Physical Broadcast Channel
• the eNB may send a Physical Control Format Indicator Channel (PCFICH) in only a portion of the first symbol period of each subframe, although depicted in the entire first symbol period 214 in FIG. 2.
• PHICH Physical HARQ Indicator Channel
• PDCCH Physical Downlink Control Channel
• the PHICH may carry information to support hybrid automatic retransmission (HARQ).
• the PDCCH may carry information on resource allocation for UEs and control information for downlink channels. Although not shown in the first symbol period in FIG. 2, it is understood that the PDCCH and PHICH are also included in the first symbol period. Similarly, the PHICH and PDCCH are also both in the second and third symbol periods, although not shown that way in FIG. 2.
• the eNB may send a Physical Downlink Shared Channel (PDSCH) in the remaining symbol periods of each subframe.
• the PDSCH may carry data for UEs scheduled for data transmission on the downlink.
• the various signals and channels in LTE are described in 3 GPP TS 36.21 1, entitled “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation," which is publicly available.
• the eNB may send the PSS, SSS and PBCH in the center 1.08 MHz of the system bandwidth used by the eNB.
• the eNB may send the PCFICH and PHICH across the entire system bandwidth in each symbol period in which these channels are sent.
• the eNB may send the PDCCH to groups of UEs in certain portions of the system bandwidth.
• the eNB may send the PDSCH to specific UEs in specific portions of the system bandwidth.
• the eNB may send the PSS, SSS, PBCH, PCFICH and PHICH in a broadcast manner to all UEs, may send the PDCCH in a unicast manner to specific UEs, and may also send the PDSCH in a unicast manner to specific UEs.
• a UE may be within the coverage of multiple eNBs.
• One of these eNBs may be selected to serve the UE.
• the serving eNB may be selected based on various criteria such as received power, path loss, signal-to-noise ratio (SNR), etc.
• FIG. 3 shows a block diagram of a design of a base station/eNB 1 10 and a UE 120, which may be one of the base stations/eNBs and one of the UEs in FIG. 1.
• the base station 110 may be the macro eNB 1 10c in FIG. 1
• the UE 120 may be the UE 120y.
• the base station 1 10 may also be a base station of some other type such as an access point including a femtocell, a picocell, etc.
• the base station 1 10 may be equipped with antennas 334a through 334t
• the UE 120 may be equipped with antennas 352a through 352r.
• a transmit processor 320 may receive data from a data source 312 and control information from a controller/processor 340.
• the control information may be for the PBCH, PCFICH, PHICH, PDCCH, etc.
• the data may be for the PDSCH, etc.
• the processor 320 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively.
• the processor 320 may also generate reference symbols, e.g., for the PSS, SSS, and cell-specific reference signal.
• a transmit (TX) multiple-input multiple-output (MIMO) processor 330 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) 332a through 332t.
• Each modulator 332 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream.
• Each modulator 332 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal.
• Downlink signals from modulators 332a through 332t may be transmitted via the antennas 334a through 334t, respectively.
• the antennas 352a through 352r may receive the downlink signals from the base station 1 10 and may provide received signals to the demodulators (DEMODs) 354a through 354r, respectively.
• Each demodulator 354 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples.
• Each demodulator 354 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols.
• a MIMO detector 356 may obtain received symbols from all the demodulators 354a through 354r, perform MIMO detection on the received symbols if applicable, and provide detected symbols.
• a receive processor 358 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 120 to a data sink 360, and provide decoded control information to a controller/processor 380.
• a transmit processor 364 may receive and process data (e.g., for the PUSCH) from a data source 362 and control information (e.g., for the PUCCH) from the controller/processor 380.
• the processor 364 may also generate reference symbols for a reference signal.
• the symbols from the transmit processor 364 may be precoded by a TX MIMO processor 366 if applicable, further processed by the modulators 354a through 354r (e.g., for SC-FDM, etc.), and transmitted to the base station 1 10.
• the uplink signals from the UE 120 may be received by the antennas 334, processed by the demodulators 332, detected by a MIMO detector 336 if applicable, and further processed by a receive processor 338 to obtain decoded data and control information sent by the UE 120.
• the processor 338 may provide the decoded data to a data sink 339 and the decoded control information to the controller/processor 340.
• the controllers/processors 340 and 380 may direct the operation at the base station 110 and the UE 120, respectively.
• the processor 340 and/or other processors and modules at the base station 110 may perform or direct the execution of various processes for the techniques described herein.
• the processor 380 and/or other processors and modules at the UE 120 may also perform or direct the execution of functional blocks, and/or other processes for the techniques described herein.
• the memories 342 and 382 may store data and program codes for the base station 1 10 and the UE 120, respectively.
• a scheduler 344 may schedule UEs for data transmission on the downlink and/or uplink.
• the UE 120 for wireless communication includes means for detecting interference from an interfering base station during a connection mode of the UE, means for selecting a yielded resource of the interfering base station, means for obtaining an error rate of a physical downlink control channel on the yielded resource, and means, executable in response to the error rate exceeding a predetermined level, for declaring a radio link failure.
• the aforementioned means may be the processor(s), the controller/processor 380, the memory 382, the receive processor 358, the MIMO detector 356, the demodulators 354a, and the antennas 352a configured to perform the functions recited by the aforementioned means.
• the aforementioned means may be a module or any apparatus configured to perform the functions recited by the aforementioned means.
• LTE may support interference measurement on a newly introduced, dedicated resource.
• the dedicated resource is introduced as "Interference Measurement Resource (IMR)" in the LTE Rel-11 specification.
• An IMR represents a set of resource elements (REs) on which the UE measures interference in an implementation-dependent way.
• An IMR may be given by a 4-port zero power channel state information reference signal (ZP-CSI-RS) resource.
• ZP-CSI-RS 4-port zero power channel state information reference signal
• the network may be responsible for ensuring that the interference created/measured on the IMR is representative of the interference that the UE will encounter during actual PDSCH transmissions.
• IMR allocation by the network may follow two paradigms. In one paradigm, judicious assignment of IMRs may be based on careful network planning.
• IMRs may be optimized for specific interference hypotheses.
• assignment of IMRs may be based on a randomized assignment without network planning.
• the assignment of IMRs may be based on a form of cell ID (details below). This assignment avoids the need for network planning. Good performance may be achieved as long as the assignment procedures avoid undesired overlap between IMRs.
• an IMR may consist of the four resource elements defined by one ZP-CSI-RS resource. IMR assignment may be performed by selecting two ZP-CSI-RS resources and distributing the four resource elements (REs) of the IMR among the eight resource elements (REs) defined by the two ZP-CSI-RS resources. Without deciding how the assignment of the four resource elements out of the eight resource elements should be performed, there is a possibility that two IMRs may overlap by three or more resource elements (REs) which is undesirable. Further, signaling may need to be determined for the assignment of the IMRs.
• REs resource elements
• assignment of IMRs may be tied to a (virtual) cell ID. Also, it can be designed such that any two IMRs may overlap by at most two resource elements (REs). This method minimizes planning effort associated with IMRs.
• the selection of the resource elements (REs) used for interference measurement may be based on some form of cell ID. The possible options may include:
• each IMR could be associated with a new virtual cell ID (e.g., in the range from
• each IMR may use the same virtual cell ID as a non-zero power channel state information reference signal (NZP-CSI-RS) with configured index; or
• Time domain hopping may be beneficially employed with the selection of resource elements changing on a per-subframe basis.
• the cell ID which configures the IMR resource elements may be sub frame dependent, i.e., it may change from subframe to subframe.
• the sequence of cell ID values may follow a signaled or predetermined hopping pattern.
• the cell ID in a given subframe may be derived based on adding the subframe number (or some function thereof) to a signaled baseline cell ID (modulo the maximum range of cell IDs).
• Another design objective may be to minimize a worst-case overlap between IMR resource elements associated with different virtual cell IDs.
• the embodiments herein target a worst case overlap of two resource elements (REs).
• FIGs. 4A-C illustrate resource element assignments using a two stage process. Randomization of the IMR may consist of two stages. Illustrated in FIG. 4A is Stage 1, where two out of a total of ten ZP-CSI-RS resources are selected. In the example of FIG. 4A, ten ZP-CSI-RS resources from index zero through nine are shown. The two resources with index values of 1 and 3 are selected. The two resources use the two blocks of Pattern 2 (shown in FIG. 4B). Each ZP-CSI-RS resource is defined by a block of four resource elements as in the LTE specification. Picking two out of ten yields forty five different combinations (ten choose two). Illustrated in FIG. 4B is Stage 2, where judicious resource element assignment is performed. Judicious resource element assignment within the two selected ZP-CSI-RS resources according to the "codebook" as illustrated. No two pairs of patterns overlap by more than two resource elements.
• the construction of the Stage 2 patterns may be based on an enumeration.
• the enumeration of odd numbered patterns i.e., Patterns 1, 3, 5, 7, 9, 1 1
• A defines an assignment of two resources to a resource block.
• [ 4 44] defines two resource blocks with the sub-pattern A in a first (or left) resource block repeated in the second (or right) resource block.
• the enumeration of even numbered patterns i.e., Patterns 2, 4, 6, 8, 10, 12
• [& ⁇ ] defines two resource blocks with the sub- pattern A in a first (or left) resource block inverted in the second (or right) resource block.
• there are 4 choose 2 combinations 6 (i.e.,
• the assignment process above may satisfy the design constraint of no more than two resource elements overlapping. If the two out of ten patterns selected in Stage 1 are not identical, then regardless of the Stage 2 pattern selection, there cannot be more than two resource elements overlapping (even if the Stage 2 patterns are the same). This is because for any of the Stage 2 patterns, each half contains only two resource elements. If the two out of ten patterns selected in Stage 1 are identical, then since any pair of two Stage 2 patterns has at most two resource elements overlap, the constraint is also satisfied.
• FIGs. 5A-B illustrate resource element assignments for two cells.
• the first cell, in FIG. 5A is selected for ZP-CSI-RS resources at index 1 and 3, with Pattern 2 of FIG. 4B.
• the second cell, in FIG. 5B is selected for ZP-CSI-RS resources at index 1 and 6, with Pattern 4 of FIG. 4B.
• the Stage 1 selection for the first and second cells therefore, has one common or overlapping block (resource at index 1).
• the ZP-CSI-RS resources may overlap in the resource index 1, as illustrated in FIG. 5C.
• one resource element (RE) overlaps in ZP-CSI-RS resources of index 1 (shown in OVERLAP' of FIG. 5C).
• FIG. 5D illustrates an example where there is no overlap in Stage 1 blocks
• FIG. 5E illustrates an example where both Stage 1 blocks overlap.
• cells in the Stage 1 process selected two non-overlapping resource blocks. For example, a first cell selected resource blocks at index 1 and 3. A second cell selected resource blocks at index 2 and 6. For Stage 2, the first cell selected Pattern 2, and the second cell selected Pattern 4.
• the Stage 1 resource blocks do not overlap, there may not be any overlapping resource elements for the two cells.
• no resource elements may overlap, and the constraint for no more than two overlapping resource elements is satisfied.
• cells in the Stage 1 process selected two overlapping resource blocks. For example, a first cell selected resource blocks at index 1 and 3. A second cell selected resource blocks at index 1 and 3.
• Stage 2 the first cell selected Pattern 2, and the second cell selected Pattern 4.
• both Stage 1 resource blocks overlap. If the resource elements within the blocks were randomly selected, the resource elements may overlap by any number of resource elements from zero to four. However, because the Stage 2 resource elements are judiciously assigned as shown in Pattern 1 through Pattern 12 in FIGs. 4B and 4C, the resource elements in FIG. 5E may not overlap by more than two resource elements.
• the resource block at index 1 has an overlap at the top left corner.
• the resource block at index 3 has an overlap at the bottom right corner. This results in an overlap of only two resource elements (REs), and the constraint for no more than two overlapping resource elements is satisfied.
• REs resource elements
• the achievable reuse factor reflects the achievable degree of randomization.
• the index of the Stage 1 pattern is given by the function: floor(x/12).
• the floor function gives the largest integer not greater than a value. For example, the floor of 2.5 is 2.
• the index of the Stage 2 pattern is given by the function: mod(x, 12).
• the modulo (or mod) function gives the remainder of a division operation. For example, 8 mod 5 is 3. Further details of the disclosure are provided below.
• IMR interference measurement resource
• Stage 1 Pick two out of ten ZP-CSI-RS resources. This gives a total of forty five different combinations (ten choose two).
• Stage 2 Pick four resource elements out of the eight resource elements defined by the selected two ZP CSI-RS resources. The selection is performed by picking one of the twelve patterns shown in FIGs. 4B-C.
• the patterns are constructed in a way that ensures that no more than two resource elements overlap between any two patterns. Indeed, it is easy to see that the twelve patterns in FIGs. 4B- C satisfy this property.
• the following approach may be used. Starting from the six (namely four choose two) possible ways of allocating two resource elements to a single ZP CSI-RS resource (say, the left group within each pattern) we construct the odd numbered patterns by duplicating the pattern and the even numbered patterns by grouping the left pattern with its inverted pattern. This yields a total of twelve patterns which exhausts all possible ways of allocating REs such that no more than two resource elements overlap.
• Stage 2 The index of the pattern selected as part of Stage 2 is given by mod(x, 12).
• the present disclosure provides techniques and methods for assigning interference measurement resources (IMRs) including the following proposals.
• Adoption of the pseudo-random IMR assignment procedure may avoid cell planning by tying the IMR allocation to some form or (virtual) cell ID.
• Selection of the IMR REs may be performed according to the two-step procedure outlined above which ensures a worst-case overlap of two resource elements (REs).
• method 600 operable by a user entity, such as, for example, a UE, a terminal, a mobile station, a subscriber unit, a station, or the like.
• a user entity such as, for example, a UE, a terminal, a mobile station, a subscriber unit, a station, or the like.
• method 600 describes a procedure to measure interference resources.
• the method 600 may involve, at 602, receiving at least one identifier wherein the at least one identifier determines, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource.
• the at least one interference measurement resource may include a number of resource elements out of a set of resource elements.
• the method 600 may involve, at 604, measuring interference based at least in part on the at least one interference measurement resource.
• method 700 operable by a network entity, such as, for example, a femtocell, a macrocell, a picocell, or the like.
• method 700 describes a procedure to assign interference measurement resources.
• the method 700 may involve, at 702, transmitting an identifier of a network entity to at least one mobile entity, the identifier determining, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource.
• the at least one interference measurement resource may include a number of resource elements out of a set of resource elements.
• the method 700 may involve, at 704, receiving channel state information (CSI) reports from at least one mobile entity based on the at least one interference measurement resource.
• CSI channel state information
• FIG. 8 shows an embodiment of an apparatus for measure interference resources, in accordance with the methodology of FIG. 6.
• an exemplary apparatus 800 may be configured as a user entity (e.g., a UE, a terminal, a mobile station, a subscriber unit, a station, or the like) in a wireless network, or as a processor or similar device/component for use within the network entity.
• apparatus 800 may be or may include UE 120 of FIG. 3.
• the apparatus 800 may include functional blocks that may represent functions implemented by a processor, software, or combination thereof (e.g., firmware).
• apparatus 800 may include an electrical component or module 802 for receiving at least one identifier wherein the at least one identifier determines, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource.
• electrical component or module 802 may be configured for receiving the at least one interference measurement resource, where the least one interference measurement resource comprises a number of resource elements out of a set of resource elements.
• Electrical component or module 802 may be, or may include, means for receiving at least one identifier wherein the at least one identifier determines, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource.
• Electrical component or module 802 may be, or may include at least one of antennas 352a through 352r, or at least one of antennas 352a through 352r coupled to any of receive processor 358 and/or processor 380.
• the apparatus 800 may include an electrical component or module 804 for measuring interference based at least in part on the at least one interference measurement resource.
• Electrical component or module 804 may be, or may include, means for measuring interference based at least in part on the at least one interference measurement resource.
• Electrical component or module 804 may be, or may include at least one of antennas 352a through 352r, or at least one of antennas 352a through 352r coupled to any of receive processor 358 and/or processor 380.
• the apparatus 800 may optionally include a processor component 850 having at least one processor, in the case of the apparatus 800 configured as a user entity (e.g., a UE, a terminal, a mobile station, a subscriber unit, a station, or the like), rather than as a processor.
• the processor 850 in such case, may be in operative communication with the components 802-804 via a bus 852 or similar communication coupling.
• the processor 850 may effect initiation and scheduling of the processes or functions performed by electrical components 802-804.
• the apparatus 800 may include a radio transceiver component 854.
• a stand alone receiver and/or stand alone transmitter may be used in lieu of or in conjunction with the transceiver 854.
• the apparatus 800 may also include a network interface (not shown) for connecting to one or more core network entities.
• the apparatus 800 may optionally include a component for storing information, such as, for example, a memory device/component 856.
• the computer readable medium or the memory component 856 may be operatively coupled to the other components of the apparatus 800 via the bus 852 or the like.
• the memory component 856 may be adapted to store computer readable instructions and data for effecting the processes and behavior of the components 802-804, and subcomponents thereof, or the processor 850, or the methods disclosed herein.
• the memory component 856 may retain instructions for executing functions associated with the components 802-804. While shown as being external to the memory 856, it is to be understood that the components 802-804 can exist within the memory 856.
• the components in FIG. 8 may comprise processors, electronic devices, hardware devices, electronic sub-components, logical circuits, memories, software codes, firmware codes, etc., or any combination thereof.
• FIG. 9 shows an embodiment of an apparatus for assigning interference measurement resources, in accordance with the methodology of FIG. 7.
• an exemplary apparatus 900 may be configured as a network entity (e.g., a femtocell, a macrocell, a picocell, or the like) in a wireless network, or as a processor or similar device/component for use within the network entity.
• apparatus 900 may be, or may include, base station 1 10 of FIG. 3.
• the apparatus 900 may include functional blocks that can represent functions implemented by a processor, software, or combination thereof (e.g., firmware).
• apparatus 900 may include an electrical component or module 902 for transmitting an identifier of a network entity to at least one mobile entity, the identifier determining, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource.
• the at least one interference measurement resource may include a number of resource elements out of a set of resource elements.
• Electrical component or module 902 may be, or may include, means for transmitting an identifier of a network entity to at least one mobile entity, the identifier determining, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource.
• Electrical component or module 902 may be, or may include at least one of antennas 334a through 334t, or at least one of antennas 334a through 334t coupled to any of transmit processor 320 and/or processor 340.
• the apparatus 900 may include an electrical component or module 904 for receiving channel state information (CSI) reports from at least one mobile entity based on the at least one interference measurement resource.
• Electrical component or module 904 may be, or may include, means for receiving channel state information (CSI) reports from at least one mobile entity based on the at least one interference measurement resource.
• Electrical component or module 904 may be, or may include, at least one of antennas 334a through 334t, or at least one of antennas 334a through 334t coupled to any of transmit processor 320 and/or processor 340.
• the apparatus 900 may optionally include a processor component 950 having at least one processor, in the case of the apparatus 900 configured as a network entity (e.g., a femtocell, a macrocell, a picocell, or the like), rather than as a processor.
• the processor 950 in such case, may be in operative communication with the components 902-904 via a bus 952 or similar communication coupling.
• the processor 950 may effect initiation and scheduling of the processes or functions performed by electrical components 902-904.
• the apparatus 900 may include a radio transceiver component 954.
• a stand alone receiver and/or stand alone transmitter may be used in lieu of or in conjunction with the transceiver 954.
• the apparatus 900 may also include a network interface (not shown) for connecting to one or more core network entities.
• the apparatus 900 may optionally include a component for storing information, such as, for example, a memory device/component 956.
• the computer readable medium or the memory component 956 may be operatively coupled to the other components of the apparatus 900 via the bus 952 or the like.
• the memory component 956 may be adapted to store computer readable instructions and data for effecting the processes and behavior of the components 902-904, and subcomponents thereof, or the processor 950, or the methods disclosed herein.
• the memory component 956 may retain instructions for executing functions associated with the components 902-904. While shown as being external to the memory 956, it is to be understood that the components 902-904 can exist within the memory 956.
• the components in FIG. 9 may comprise processors, electronic devices, hardware devices, electronic sub-components, logical circuits, memories, software codes, firmware codes, etc., or any combination thereof.
• DSP digital signal processor
• ASIC application specific integrated circuit
• FPGA field programmable gate array
• a general- purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine.
• a processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
• a software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.
• An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium.
• the storage medium may be integral to the processor.
• the processor and the storage medium may reside in an ASIC.
• the ASIC may reside in a user terminal.
• the processor and the storage medium may reside as discrete components in a user terminal.
• the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium.
• Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another.
• a storage media may be any available media that can be accessed by a general purpose or special purpose computer.
• such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium.
• Disk and disc includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer- readable media.

Landscapes

• Engineering & Computer Science (AREA)
• Signal Processing (AREA)
• Computer Networks & Wireless Communication (AREA)
• Quality & Reliability (AREA)
• Mobile Radio Communication Systems (AREA)

Priority Applications (4)

Applications Claiming Priority (4)

Publications (1)

Family

ID=50385085

Family Applications (1)

Country Status (5)

Cited By (2)

Families Citing this family (20)

Family Cites Families (15)

• 2013
  • 2013-02-28 US US13/781,605 patent/US9609537B2/en active Active
  • 2013-09-24 WO PCT/US2013/061498 patent/WO2014052341A1/en not_active Ceased
  • 2013-09-24 EP EP13774870.3A patent/EP2901747B1/en active Active
  • 2013-09-24 JP JP2015534605A patent/JP6309529B2/ja active Active
  • 2013-09-24 EP EP20216700.3A patent/EP3836610B1/en active Active
  • 2013-09-24 CN CN201380049989.9A patent/CN104685918B/zh active Active
• 2017
  • 2017-02-17 US US15/435,819 patent/US9936494B2/en active Active
• 2018
  • 2018-03-14 JP JP2018046743A patent/JP6615927B2/ja active Active

Non-Patent Citations (4)

Also Published As

Similar Documents

Legal Events