Interference cancellation in dynamic spectrum sharing

Abstract

The present disclosure relates to interference cancellation in dynamic spectrum sharing. The present application relates to apparatuses and components, including devices and means for canceling reference signal interference in a dynamic spectrum sharing network, systems, and methods.

Description

Background Technology

[0001] Dynamic Spectrum Sharing (DSS) has been introduced in the 3GPP 5G New Radio (NR) framework to share spectrum between LTE and NR cells. The DSS framework allows NR cells to rate match around the LTE reference signal, which would otherwise lead to strong interference and compromise spectrum efficiency. Attached Figure Description

[0002] Figure 1 A cellular system according to some implementation schemes is shown.

[0003] Figure 2 A pair of orthogonal frequency division multiplexing (OFDM) symbols according to some implementation schemes is shown.

[0004] Figure 3 Another pair of OFDM symbols is shown according to some implementation schemes.

[0005] Figure 4 Another pair of OFDM symbols is shown according to some implementation schemes.

[0006] Figure 5 The extraction and elimination operations are shown based on several aspects.

[0007] Figure 6 A Kalman state buffer according to some implementation schemes is shown.

[0008] Figure 7 The process for frequency offset estimation according to some implementation schemes is shown.

[0009] Figure 8 The operational flow / algorithm structure according to some implementation schemes is shown.

[0010] Figure 9 Another operational flow / algorithm structure according to some implementation schemes is shown.

[0011] Figure 10 User equipment according to some implementation schemes is shown. Detailed Implementation

[0012] The following detailed description relates to the accompanying drawings. The same reference numerals may be used in different drawings to identify the same or similar elements. In the following description, specific details, such as particular structures, architectures, interfaces, technologies, etc., are set forth for illustrative and non-limiting purposes to provide a thorough understanding of all aspects of the subject matter. However, it will be apparent to those skilled in the art that all aspects of the subject matter may be practiced in other examples departing from these specific details. In some cases, descriptions of well-known devices, circuits, and methods have been omitted so as not to obscure the description of the subject matter with unnecessary detail. For the purposes of this document, the phrase "A or B" means (A), (B), or (A and B).

[0013] The following is a glossary of terms that may be used in this disclosure.

[0014] As used herein, the term "circuit" means, is part of, or includes the following: hardware components such as electronic circuits, logic circuits, processors (shared, dedicated, or grouped) or memories (shared, dedicated, or grouped), application-specific integrated circuits (ASICs), field-programmable devices (FPDs) (e.g., field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), complex PLDs (CPLDs), high-capacity PLDs (HCPLDs), structured ASICs, or programmable system-on-chips (SoCs)), digital signal processors (DSPs), etc. In some respects, a circuit may execute one or more software or firmware programs to provide at least some of the said functions. The term "circuit" may also refer to a combination of one or more hardware elements and program code for performing the functions (or a combination of circuits used in an electrical or electronic system). In these respects, the combination of hardware elements and program code may be referred to as a particular type of circuit.

[0015] As used herein, the term "processor circuit" means, is part of, or includes the following: a circuit capable of sequentially and automatically performing a series of arithmetic or logical operations or recording, storing, or transmitting digital data. The term "processor circuit" may also refer to an application processor, baseband processor, central processing unit (CPU), graphics processing unit, single-core processor, dual-core processor, triple-core processor, quad-core processor, or any other device capable of executing or otherwise operating computer-executable instructions (such as program code, software modules, and / or functional procedures).

[0016] As used herein, the term "interface circuit" refers to, is part of, or includes a circuit that enables the exchange of information between two or more components or devices. The term "interface circuit" can refer to one or more hardware interfaces, such as buses, I / O interfaces, peripheral component interfaces, network interface cards, etc.

[0017] As used herein, the term "user equipment" or "UE" refers to equipment of a remote user that has radio communication capabilities and can describe network resources in a communication network. Furthermore, the term "user equipment" or "UE" may be considered synonymous and may refer to a client, mobile phone, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, subscriber, user, remote station, access agent, user agent, receiver, radio equipment, reconfigurable radio equipment, reconfigurable mobile device, etc. Additionally, the term "user equipment" or "UE" can include any type of wireless / wired equipment or any computing device that includes a wireless communication interface.

[0018] As used herein, the term "computer system" means any type of interconnected electronic device, computer device, or component thereof. Additionally, the term "computer system" or "system" may refer to the various components of a computer that are communicatively coupled to each other. Furthermore, the term "computer system" or "system" may refer to multiple computer devices or multiple computing systems that are communicatively coupled to each other and configured to share computing resources or network resources.

[0019] As used herein, the term "resource" refers to physical or virtual devices, physical or virtual components within a computing environment, or physical or virtual components within a specific device, such as computer equipment, mechanical equipment, memory space, processor / CPU time, processor / CPU utilization, processor and accelerator load, hardware time or utilization, power supply, input / output operations, port or network sockets, channel / link allocation, throughput, memory utilization, storage, network, databases and applications, units of workload, etc. "Hardware resource" can refer to computing, storage, or networking resources provided by physical hardware components. "Virtualized resource" can refer to computing, storage, or networking resources provided by virtualization infrastructure to applications, devices, systems, etc. The terms "network resource" or "communication resource" can refer to resources that computer equipment / systems can access via a communication network. The term "system resource" can refer to any kind of shared entity providing services and can include computing or network resources. System resources can be considered as a coherent set of functions, network data objects, or services accessible through a server, wherein such system resources reside on a single host or multiple hosts and are clearly identifiable.

[0020] As used herein, the term "channel" refers to any tangible or intangible transmission medium used for transmitting data or data streams. The term "channel" may be synonymous or equivalent with "communication channel," "data communication channel," "transmission channel," "data transmission channel," "access channel," "data access channel," "link," "data link," "carrier," "radio frequency carrier," or any other similar term indicating a path or medium through which data is transmitted. Additionally, as used herein, the term "link" refers to a connection between two devices used for transmitting and receiving information.

[0021] As used in this article, the terms "instantiate" and "instantiate" refer to the creation of an instance. "Instance" also refers to the concrete occurrence of an object, which may occur, for example, during the execution of program code.

[0022] The term "connection" can mean that two or more elements at a common communication protocol layer have an established signaling relationship with each other through a communication channel, link, interface, or reference point.

[0023] As used herein, the term "network element" refers to physical or virtualized equipment or infrastructure used to provide wired or wireless communication network services. The term "network element" may be considered synonymous with or referred to as networked computers, network hardware, network equipment, network nodes, virtualized network functions, etc.

[0024] The term "information element" refers to a structural element that contains one or more fields. The term "field" refers to the individual content of an information element, or the data element that contains that content. An information element may include one or more additional information elements.

[0025] Figure 1 A cellular system 100 is shown according to some aspects. The cellular system 100 may include a first set of devices designed to communicate using LTE radio access technology and a second set of devices designed to communicate using NR radio access technology.

[0026] LTE equipment may include LTE user equipment (UE) 104A, LTE UE 108A, evolved Node B (eNB) 112A, and eNB 116A. NR equipment may include NR UE 120B and NR UE 124B. Cellular system 100 may also include DSS base station 128, which is capable of operating as an eNB providing LTE cells or a gNB providing NR cells.

[0027] In an LTE cell, a Cell-Specific Reference Signal (CRS) can be transmitted on the downlink to facilitate Channel Quality Information (CQI) reporting, demodulation, cell selection (reselection), and handover operations. The DSS base station 128 can effectively mitigate CRS interference from CRS transmitted in the LTE serving cell provided by the DSS base station 128. This can be accomplished through the rate matching resource element (RE) tone of the NR cell corresponding to the CRS. Since the CRS will be on the same RE as the serving cell's CRS, CRS interference from conflicting neighboring cells can also be mitigated in this way.

[0028] eNB 112A and eNB 116A can be non-collision neighbors. Therefore, CRS transmitted by eNB 112A and eNB 116A may cause non-collision interference on the RE of the NR cell. This interference may limit system throughput or capacity. It is possible to rate match the RE tone of the NR cell corresponding to the CRS of the non-collision neighbor. However, this may result in additional overhead because Physical Downlink Shared Channel (PDSCH) transmission may not be allowed on some OFDM symbols corresponding to the CRS of the non-collision neighbor.

[0029] This disclosure describes embodiments for non-collision CRS interference cancellation in NR cells to mitigate LTE-CRS interference. As described herein, CRS interference cancellation may include complete or partial cancellation of interference caused by CRS.

[0030] This method can resolve differences in downlink transmissions between NR and LTE cells to effectively eliminate LTE CRS interference on NR cells. These differences may be related to differences in the use of DC subcarriers and OFDM modulation. Embodiments of this disclosure illustrate at least three aspects of these differences.

[0031] The first aspect of this disclosure includes CRS extraction and elimination. In short, CRS reference symbol extraction and data RE insertion following elimination can be performed by considering the DC subcarrier.

[0032] A second aspect of this disclosure includes phase compensation for neighboring cell channel estimation. In short, due to the difference in OFDM symbol generation between LTE and NR, phase compensation for LTE CRS can be performed during channel estimation.

[0033] A third aspect of this disclosure includes neighboring cell frequency offset estimation for the CRS. In short, neighboring cell frequency offset estimation can be performed on the CRS under DSS, where OFDM symbol generation differs between LTE and NR.

[0034] These and other aspects of this disclosure will be described in more detail.

[0035] Figure 2 A pair of Orthogonal Frequency Division Multiplexing (OFDM) symbols is shown according to some implementation schemes. OFDM symbol 204 can represent a symbol in a non-collision LTE cell. OFDM symbol 208 can represent a symbol in an NR cell.

[0036] The CRS in OFDM symbol 204 can be mapped to resource elements based on a CRS shift, which is determined based on the cell ID of the LTE cell. For example, the CRS shift (CRS...) shift It can be defined as follows:

[0037] CRS shift =cell ID Modulus 6,

[0038] cell ID This is the identifier for the LTE cell. OFDM symbol 204 is shown as a CRS shift of 2. If the first resource element at the low end of the carrier bandwidth is RE0, shifting the CRS sequence by 2 will result in the CRS being located in the third resource element (RE2) and the ninth resource element (RE8) of a given resource block.

[0039] OFDM symbol 208 is shown, in which the CRS transmitted in the LTE cell is superimposed on the selected resource element. The mapping from the resource element carrying the CRS in OFDM symbol 204 to the resource element in OFDM symbol 208 can be based on the DC carrier in OFDM symbol 208.

[0040] In LTE, the DC subcarrier is reserved and not used for data transmission. In NR, the DC subcarrier is used for data transmission. Therefore, the DC subcarrier is shown in OFDM symbol 208 but not in OFDM symbol 204. Due to this difference, when mapped onto the NR resource grid, the carrier spacing of CRS versus LTE interference is not a regular grid of six resource elements.

[0041] The implementation plan takes into account the DC impact during CRS descrambling of interference. This can be accomplished by dividing the resource grid into different regions, where CRS extraction is processed separately.

[0042] The first region 212 can be defined as resource elements comprising a resource block, which includes a DC subcarrier. The second region 216 can be defined as resource blocks comprising a frequency lower than that of the first region. The third region 220 can be defined as resource blocks comprising a frequency higher than that of the first region.

[0043] In the second region 216, the CRS of resource elements from OFDM symbol 204 can be mapped to the corresponding resource elements of OFDM symbol 208. For example, the CRS of RE2 and RE8 from OFDM symbol 204 can be mapped to RE2 and RE8 of OFDM symbol 208, respectively.

[0044] In the third region 220, the CRS of resource elements from OFDM symbol 204 can be mapped to resource elements of OFDM symbol 208 at offset 1. For example, the CRS of RE2 and RE8 from OFDM symbol 204 can be mapped to RE3 and RE9 of OFDM symbol 208, respectively. This offset 1 indicates the offset of the DC subcarriers present in OFDM symbol 208.

[0045] In the first region 212, resource elements below the DC subcarrier can be mapped as described above regarding the second region 216, while resource elements above the DC subcarrier can be mapped as described above regarding the third region 220. For example... Figure 2 As shown, all resource elements in the first region 212 are above the DC subcarrier. Therefore, the CRS of resource elements from OFDM symbol 204 can be mapped to resource elements of OFDM symbol 208 at offset 1. For example, the CRS of RE2 and RE8 from OFDM symbol 204 can be mapped to RE3 and RE9 of OFDM symbol 208, respectively.

[0046] Figure 3 A pair of OFDM symbols is shown according to some implementation schemes. OFDM symbol 304 can represent a symbol in a non-collision LTE cell. OFDM symbol 308 can represent a symbol in NR cells.

[0047] In this implementation, the CRS in OFDM symbol 304 can be mapped to resource elements based on a CRS shift of 5. Therefore, the CRS can be located in the sixth resource element (RE5) and the twelfth resource element (RE11) of a given resource block.

[0048] The mapping of resource elements from OFDM symbol 304 to OFDM symbol 308 can be similar to that described above. For example, in the second region 316, the CRS of a resource element from OFDM symbol 304 can be mapped to the corresponding resource element in OFDM symbol 308. For example, the CRSs of RE5 and RE11 from OFDM symbol 304 can be mapped to RE5 and RE11 in OFDM symbol 308, respectively.

[0049] In the third region 320, the CRS of resource elements from OFDM symbol 304 can be mapped to resource elements of OFDM symbol 308 at an offset of 1. For example, CRSs RE5 and RE11 from OFDM symbol 304 can be mapped to RE6 and RE0 of OFDM symbol 208, respectively. The mapping from RE11 to RE0 can result in a CRS from resource block N of the LTE cell being mapped to resource block N+1 of the NR cell. This may result in a CRS RE not being mapped to an RE in OFDM 304 because it may be outside the carrier bandwidth of the NR cell. In some implementations, pseudo-CRS resource elements can be added to compensate for lost CRS REs to provide consistent signal processing.

[0050] In the first region 312, resource elements below the DC subcarrier can be mapped as described above regarding the second region 316, while resource elements above the DC subcarrier can be mapped as described above regarding the third region 220.

[0051] exist Figure 2 and Figure 3 In this context, the carrier bandwidth of an LTE cell is shown as equal to that of an NR cell. In other implementations, the bandwidth may differ.

[0052] Figure 4 A pair of OFDM symbols is shown in some implementations where LTE and NR cells have different bandwidths. OFDM symbol 404 can represent a symbol in a non-collision LTE cell with a first carrier bandwidth. OFDM symbol 408 can represent a symbol in an NR cell with a second carrier bandwidth greater than the first carrier bandwidth.

[0053] In this implementation, the CRS shift can be 5, as mentioned above. Figure 3 The discussion is similar. However, in this implementation, the larger carrier bandwidth of the NR cell allows the CRS RE11 of resource block N of the LTE cell to be mapped to the CRS RE0 of resource block N+1 of the NR cell at the top of the carrier bandwidth. Therefore, pseudo CRS REs are not required in this implementation.

[0054] The mapping of RE to the NR bandwidth in the first region 412, the second region 416, and the third region 420 can be similar to the discussion above.

[0055] Figure 5 The CRS extraction and elimination operation 500 according to some implementation schemes is shown.

[0056] At 504, operation 500 may include interference screening to identify non-collision interference sources. In some implementations, interference screening may include using neighboring cell information provided by the serving cell to identify neighboring eNBs that may be transmitting CRSs causing non-collision interference.

[0057] In step 508, operation 500 may further include reference symbol extraction considering the DC carrier. Reference symbol extraction can be performed on the resource element information of the NR OFDM symbols from the symbol buffer 502. The NR OFDM symbols can be compared with the above information regarding... Figures 2 to 4 The description is similar. Reference symbol extraction can determine the CRS shift based on the cell identifier of the identified interference, and can map the CRS RE of the LTE cell to the resource elements of the NR OFDM symbol based on the area-specific mapping as described herein.

[0058] The RE extracted at 508 can be used as the basis for CRS construction at 510. CRS construction can be performed to estimate the LTE channel interfering with the NR reference element based on the transmitted CRS.

[0059] In the 512, the CRS construction may include reference signal descrambling and frequency filtering to isolate the frequency components of the CRS. The output from the 512 may include the RS descrambled output, which can be stored in a least-squares (LS) channel estimation buffer, and the frequency direction-filtered output, which can be stored in a frequency-domain (FD) channel estimation buffer. The signals in these buffers may not have undergone phase correction.

[0060] After 512, CRS interference cancellation (IC) time filtering can be performed on the LTE channel estimation.

[0061] The NROFDM symbols defined in Section 5.4 of 3GPP TS 38.211 v16.6.0 (2021-06-30) and the LTEOFDM symbols defined in 3GPP TS 36.211 v16.6.0 (2021-06-30) have different phases. For example, the NR signal after modulation and up-conversion to the carrier frequency (excluding the Physical Random Access Channel (PRACH) signal and the Remote Interference Management (RIM) Reference Signal (RS)) is defined in 3GPP TS 38.211 as follows:

[0062] in

[0063]

[0064] and

[0065]

[0066] in It is the time-continuous signal on the antenna port p and subcarrier spacing configuration μ of OFDM symbol l in the subframe, and κ is T s (The basic time unit of LTE) and T c The ratio between (the basic time unit of NR).

[0067] LTE OFDM symbols can be defined as

[0068]

[0069] in It is the time-continuous baseband signal of antenna port p and SC-FDMA / OFDM symbol l in the time slot.

[0070] These differences can cause phase distortion in the LTE CRS symbols received by the NR UE from interfering cells. Phase correction can be used to compensate for the effects of phase differences during CRS-IC time filtering used for LTE channel estimation.

[0071] In short, CRS-IC timing filtering may include timing filtering with phase compensation to align the CRS symbol with the reference symbol at 516, and then rotate the phase back to the original phase at 524. In some implementations, Kalman filtering may be used to perform this phase compensation for the LTE CRS during timing filtering.

[0072] Figure 6 The operation of a Kalman state buffer according to some implementation schemes is shown.

[0073] During Kalman forward filtering, the phase of each CRS symbol is aligned with a reference phase to facilitate coherent filtering. For CRS ports 0 / 1, the phase can be aligned with the phase of OFDM symbol 0. For CRS ports 2 / 3, the phase can be aligned with the phase of OFDM symbol 1. As shown, Kalman forward filtering aligns the phases of CRS 4, CRS 7, and CRS 11 with CRS 0. When a connection is established, the phase offset between CRS symbol 0 / 1 and other CRS symbols in the same transmission group (e.g., Transmission Time Interval (TTI)) may only need to be calculated once. The CRS symbol # (or CRS#) used in this paper can refer to OFDM symbol # with CRS components.

[0074] After Kalman forward filtering and before CRS elimination, a Kalman backward smoothing and elimination process is performed, in which the phase is rotated back to the original phase of the corresponding CRS OFDM symbol.

[0075] In some implementations, time-based filtering methods different from Kalman filtering can be used. For example, in some implementations, a finite impulse response (FIR) filter can be used. The compensation method using an FIR filter can be similar to that of a Kalman filter. Using an FIR filter, the filtered CRS can be aligned to the same phase as CRS symbol 0, while the phase of the descrambled original CRS is maintained in the interference channel estimation (CE) buffer 520. At 524, the original CRS data can be used to rotate the phase back to the original phase.

[0076] After CRS construction 510, process 500 may include interference cancellation in 528. Interference cancellation may include subtracting the constructed CRS from the extracted RE, which includes CRS interference. Once the interference is eliminated, interference-free (or interference-reduced) data can be written back to symbol buffer 502. The extraction mode used to extract the RE can be used to write the RE back to symbol buffer 502.

[0077] Figure 7 A process 700 for frequency offset estimation is provided according to some implementation schemes. It may be desirable to perform frequency offset estimation on interfering cells to improve CRS-IC performance. In some implementations, the frequency offset estimate can be calculated based on the phase difference between two CRS symbols (e.g., CRS 0 and CRS 7).

[0078] In 704, process 700 may include reference symbol extraction taking into account the DC carrier. Reference symbol extraction may include the above-mentioned... Figure 5 The process is similar to that discussed in sections 508 and 512. The extracted reference symbol can be symbol 0, which includes components of the CRS from the interfering cell. The extraction of the reference symbol can be based on the above discussion regarding... Figure 5 The discussion is similar to non-conflicting interference information.

[0079] In step 708, process 700 may further include the extraction of another reference symbol considering the DC carrier. The extracted reference symbol may be symbol 7, which also includes components of the CRS from the interfering cell. The extraction of the reference symbol can be based on the above regarding... Figure 5 The discussion is similar to non-conflicting interference information.

[0080] Process 700 may also include frequency offset estimation in 712. Frequency offset estimation can be based on calculating the phase difference between the reference symbols extracted in 704 and 708. The frequency offset estimated in 712 can estimate the frequency offset caused by the oscillator frequency difference between the UE and eNB of the interfering cell.

[0081] Process 700 may also include phase compensation at 716. Phase compensation at 716 determines the phase offset present for different CRS symbols of the interfering cell received by the NR UE. This system phase offset may be due to the aforementioned NR OFDM symbol generation. At 716, this phase offset caused by UE differences in symbol generation can be excluded from the previously estimated frequency offset to compensate for system bias in the frequency offset estimation.

[0082] Figure 8 An operation flow / algorithm structure 800 is shown according to some aspects. The operation flow / algorithm structure 800 may be executed or implemented by a UE such as, for example, NR UE 120B, NR UE 124B or UE 1000; or by its components such as baseband processor 1004A.

[0083] In 804, the operation procedure / algorithm structure 800 may include cell identifiers for identifying neighboring cells transmitting the CRS. The cell identifiers may be based on neighboring cell reports provided to the NR UE by the gNB. Neighboring cells may be LTE cells providing non-collision interference. For example, the gNB may not rate-match the LTE-transmitted CRS, and as a result, the CRS may be a potential source of interference.

[0084] In 808, the operation procedure / algorithm structure 800 may also include deriving the CRS shift based on the cell identifier. The CRS shift can be determined based on the cell ID modulus 6 as described above.

[0085] The operation process / algorithm structure 800 may also include: In 812, extracting the CRS based on CRS shift and the DC subcarrier of the serving cell. CRS extraction can be based on an extraction mode with multiple regions. The first region can be defined as a resource block including the DC subcarrier. The second region can be defined as a resource block including frequencies lower than the DC subcarrier. The third region can be defined as a resource block with frequencies higher than the DC subcarrier.

[0086] CRS from neighboring cells can be mapped to resource elements of the serving cell based on different regions. For example, a CRS resource element can be mapped to a corresponding resource element in a second region, and can also be mapped to a resource element offset by 1 from the corresponding resource element in a third region, taking into account the DC subcarrier. In the first region, a CRS resource element can be mapped to a corresponding resource element below the DC subcarrier (if any), and can also be mapped to a resource element offset by 1 from the corresponding resource element above the DC subcarrier.

[0087] In 816, the operation flow / algorithm structure 800 may also include channel estimation for performing CRS. Channel estimation of CRS can be performed using a time filter with phase compensation to align multiple CRS symbols in the TTI with a reference symbol. Subsequently, the phase of the CRS symbols can be rotated back to the original phase. In some implementations, this can be accomplished using a Kalman or FIR filter.

[0088] The operation procedure / algorithm structure 800 may also include, in 820, eliminating CRS interference from the data received in the serving cell based on channel estimation. The data can then be written back to the symbol buffer. The data can be written back to the symbol buffer based on the extraction mode used to extract CRS.

[0089] Figure 9 An operational flow / algorithm structure 900 is shown according to some aspects. The operational flow / algorithm structure 900 may be executed or implemented by a UE such as, for example, NR UE 120B, NR UE 124B or UE 1000; or by its components such as baseband processor 1004A.

[0090] In 904, the operation procedure / algorithm structure 900 may include detecting interference on resource elements of the serving cell OFDM symbol from the CRS in the neighboring cell OFDM symbol.

[0091] In 908, the operation flow / algorithm structure 900 may also include the extraction of resource elements. As described elsewhere in this document, the extraction of resource elements can utilize an extraction mode with multiple regions based on CRS shift and DC carrier.

[0092] In 912, the operation procedure / algorithm structure 900 may further include constructing a CRS by compensating for the phase difference between serving cell OFDM symbols in adjacent cell OFDM symbols. The phase difference may be based on different symbol generation techniques used to generate OFDM symbols using NR and LTE technologies. In some implementations, constructing the CRS may include performing time filtering with phase compensation to compensate for the phase difference.

[0093] In some implementations, time filtering may include aligning the phases of multiple symbols in the TTI with the phase of a reference symbol. This can be done using a Kalman forward filter. Subsequently, the phases can be rotated back to the original phases of the individual symbols. This can be done using a Kalman backward smoothing and cancellation operation.

[0094] In 916, the operation procedure / algorithm structure 900 may also include interference removal from resource elements. Interference removal can remove some or all CRS interference from the resource elements of the serving cell OFDM symbol. The serving cell OFDM symbol can then be written back to the OFDM symbol buffer for further processing.

[0095] Figure 10 The UE 1000 is shown according to some aspects. The UE 1000 can be similar to or interchangeable with NR UE 120B or NR UE 124B.

[0096] The UE 1000 can be any mobile or non-mobile computing device, such as mobile phones, computers, tablets, industrial wireless sensors (e.g., microphones, carbon dioxide sensors, pressure sensors, humidity sensors, thermometers, motion sensors, accelerometers, laser scanners, fluid level sensors, stock sensors, voltmeters / ammeters, actuators, etc.), video surveillance / monitoring devices (e.g., cameras, camcorders, etc.), wearable devices (e.g., smartwatches), and loosely coupled IoT devices.

[0097] UE 1000 may include a processor 1004, RF interface circuitry 1008, memory / storage device 1012, user interface 1016, sensor 1020, drive circuitry 1022, power management integrated circuit (PMIC) 1024, antenna structure 1026, and battery 1028. The components of UE 1000 may be implemented as integrated circuits (ICs), portions of integrated circuits, discrete electronic devices or other modules, logic components, hardware, software, firmware, or combinations thereof. Figure 10 The block diagram is intended to show a high-level view of some of the components of the UE 1000. However, some of the components shown may be omitted, additional components may be present, and different arrangements of the components shown may occur in other specific implementations.

[0098] The components of UE 1000 can be coupled to various other components via one or more interconnects 1032, which can represent any type of interface, input / output, bus (local, system, or extension), transmission line, trace, optical connector, etc., allowing various circuit components (on common or different chips or chipsets) to interact with each other.

[0099] Processor 1004 may include processor circuitry such as baseband processor circuitry (BB) 1004A, central processing unit circuitry (CPU) 1004B, and graphics processing unit circuitry (GPU) 1004C. Processor 1004 may include any type of circuitry or processor circuitry that executes or otherwise operates computer-executable instructions (such as program code, software modules, or functional processes from memory / storage device 1012) to cause UE 1000 to perform the operations described herein.

[0100] In some aspects, the baseband processor circuit 1004A can access the communication protocol stack 1036 in the memory / storage device 1012 to communicate over a 3GPP-compliant network. Generally, the baseband processor circuit 1004A can access the communication protocol stack to perform the following operations: user plane functions at the PHY, MAC, RLC, PDCP, SDAP, and PDU layers; and control plane functions at the PHY, MAC, RLC, PDCP, RRC, and non-access layers. In some aspects, PHY layer operations may be additionally / alternatively performed by components of the RF interface circuit 1008.

[0101] The baseband processor circuit 1004A can generate or process baseband signals or waveforms carrying information in a 3GPP-compliant network. In some aspects, the waveforms used for NR can be based on cyclic prefix OFDM (“CP-OFDM”) in the uplink or downlink, and Discrete Fourier Transform Extended OFDM (“DFT-S-OFDM”) in the uplink.

[0102] The memory / storage device 1012 may include one or more non-transitory computer-readable media, which include instructions (e.g., a communication protocol stack 1036) that can be executed by one or more processors in processor 1004 to cause UE 1000 to perform the various operations described herein. The memory / storage device 1012 may also store CSI IMR, reports, and rate mode configuration information as described elsewhere.

[0103] The memory / storage device 1012 includes any type of volatile or non-volatile memory that can be distributed throughout the UE 1000. In some aspects, some of the memory / storage devices 1012 may be located on the processor 1004 itself (e.g., L1 and L2 cache memories), while other memory / storage devices 1012 are external to the processor 1004 but accessible via a memory interface. The memory / storage device 1012 may include any suitable volatile or non-volatile memory, such as, but not limited to, dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory, or any other type of memory device technology.

[0104] The RF interface circuit 1008 may include transceiver circuitry and a radio frequency front-end module (RFEM), which allows the UE 1000 to communicate with other devices via a radio access network. The RF interface circuit 1008 may include various components arranged in the transmit or receive path. These components may include, for example, switches, mixers, amplifiers, filters, synthesizer circuitry, control circuitry, etc.

[0105] In the receiving path, the RFEM can receive the radiated signal from the air interface via antenna structure 1026 and continue to filter and amplify the signal (using a low-noise amplifier). This signal can be provided to the receiver of the transceiver, which downconverts the RF signal into a baseband signal that is provided to the baseband processor of processor 1004.

[0106] In the transmission path, the transceiver's transmitter upconverts the baseband signal received from the baseband processor and provides the RF signal to the RFEM. The RFEM amplifies the RF signal using a power amplifier before it is radiated across the air interface via antenna 1026.

[0107] In all respects, the RF interface circuit 1008 can be configured to transmit / receive signals in a manner compatible with NR access technology.

[0108] Antenna 1026 may include antenna elements to convert electrical signals into radio waves for propagation through the air and to convert received radio waves back into electrical signals. These antenna elements may be arranged in one or more antenna panels. Antenna 1026 may have omnidirectional, directional, or combinations thereof antenna panels to enable beamforming and multiple-input / multiple-output communication. Antenna 1026 may include microstrip antennas, printed antennas fabricated on the surface of one or more printed circuit boards, patch antennas, phased array antennas, etc. Antenna 1026 may have one or more panels designed for a specific frequency band included in FR1 or FR2.

[0109] User interface circuitry 1016 includes various input / output (I / O) devices designed to enable users to interact with UE 1000. User interface circuitry 1016 includes input device circuitry and output device circuitry. Input device circuitry includes any physical or virtual means for accepting input, particularly including one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, a keypad, a mouse, a touchpad, a touchscreen, a microphone, a scanner, a headset, etc. Output device circuitry includes any physical or virtual means for displaying information or otherwise conveying information (such as sensor readings, actuator positions, or other similar information). Output device circuitry may include any number or combination of audio or visual displays, particularly including one or more simple visual outputs / indicators (e.g., binary status indicators such as light-emitting diodes "LEDs") and multi-character visual outputs, or more complex outputs such as display devices or touchscreens (e.g., liquid crystal displays "LCDs", LED displays, quantum dot displays, projectors, etc.), wherein the output of characters, graphics, multimedia objects, etc., is generated or produced by the operation of UE 1000.

[0110] Sensor 1020 may include devices, modules, or subsystems designed to detect events or changes in their environment and transmit information about the detected events (sensor data) to other devices, modules, subsystems, etc. Examples of such sensors include, in particular: inertial measurement units including accelerometers, gyroscopes, or magnetometers; microelectromechanical systems (MEMS) or nanoelectromechanical systems (NEMS) including triaxial accelerometers, triaxial gyroscopes, or magnetometers; level sensors; flow sensors; temperature sensors (e.g., thermistors); pressure sensors; barometric pressure sensors; gravimeters; altimeters; image capture devices (e.g., cameras or lensless aperture sensors); light detection and ranging sensors; proximity sensors (e.g., infrared radiation detectors, etc.); depth sensors; ambient light sensors; ultrasonic transceivers; and microphones or other similar audio capture devices.

[0111] The driving circuit 1022 may include software and hardware elements for controlling specific devices embedded in, attached to, or otherwise communicatively coupled to the UE 1000. The driving circuit 1022 may include various drivers that allow other components to interact with or control various input / output (I / O) devices that may exist within or be connected to the UE 1000. For example, the driving circuit 1022 may include: a display driver for controlling and allowing access to a display device; a touchscreen driver for controlling and allowing access to a touchscreen interface; a sensor driver for acquiring sensor readings of the sensor circuit 1020 and controlling and allowing access to the sensor circuit 1020; a driver for acquiring actuator positions of electromechanical components or controlling and allowing access to electromechanical components; a camera driver for controlling and allowing access to an embedded image capture device; and an audio driver for controlling and allowing access to one or more audio devices.

[0112] The PMIC 1024 manages the power supplied to various components of the UE 1000. Specifically, relative to the processor 1004, the PMIC 1024 controls power selection, voltage scaling, battery charging, or DC-DC conversion.

[0113] Battery 1028 can power UE 1000, but in some examples, UE 1000 may be mounted in a fixed location and may have a power source coupled to the mains. Battery 1028 may be a lithium-ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, etc. In some specific implementations, such as in vehicle-based applications, battery 1028 may be a typical lead-acid automotive battery.

[0114] As is widely recognized, the use of personally identifiable information should comply with privacy policies and practices that are generally accepted to meet or exceed industry or governmental requirements for protecting user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly explained to users.

[0115] For one or more aspects, at least one of the components shown in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, or methods as described in the Examples section below. For example, the baseband circuitry described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples below. As another example, circuitry associated with the UE, base station, network element, etc., described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples shown in the Examples section below.

[0116] Example

[0117] Further exemplary aspects are provided in the following sections.

[0118] Example 1 includes a method comprising: identifying cell identifiers of neighboring cells that transmit a cell-specific reference signal (CRS); deriving a CRS shift based on the cell identifiers; extracting the CRS based on the CRS shift and a direct current (DC) subcarrier of the serving cell; performing channel estimation of the CRS; and eliminating CRS interference from data received in the serving cell based on the channel estimation.

[0119] Example 2 includes the method of Example 1, wherein extracting CRS includes: identifying extraction patterns for first, second, and third regions comprising the carrier bandwidth of the serving cell, the first region comprising a first resource block (RB) containing a DC subcarrier, the second region comprising one or more RBs at frequencies below the first RB, and the third region comprising one or more RBs at frequencies above the first RB.

[0120] Example 3 includes the method of Example 2, and further includes: writing data to an orthogonal frequency division multiplexing (OFDM) symbol buffer based on the extraction mode.

[0121] Example 4 includes the method of Example 2, wherein extracting CRS includes: mapping CRS resource elements (REs) from neighboring cells to corresponding REs in a second region; and mapping CRS REs to REs offset by 1 from corresponding REs in a third region.

[0122] Example 5 includes the method of Example 4, and further includes: determining that a first CRS RE will be mapped to a first RE outside the carrier bandwidth; generating a pseudo-reference signal based on the first CRS RE; and further performing channel estimation based on the pseudo-reference signal.

[0123] Example 6 includes the method of Example 2, wherein extracting CRS includes: identifying a first RE in a first region with a frequency lower than that of the DC subcarrier; identifying a second RE in a second region with a frequency higher than that of the DC subcarrier; mapping CRS REs from neighboring cells to the corresponding REs of the first RE; and mapping CRS REs from neighboring cells to REs offset by 1 from the corresponding RE of the second RE.

[0124] Example 7 includes the method of Example 1, wherein deriving the CRS shift includes: determining that the CRS shift is equal to the cell identifier modulus 6.

[0125] Example 8 includes the method of Example 1, wherein the carrier bandwidth of the serving cell is greater than the carrier bandwidth of the neighboring cells.

[0126] Example 9 includes a method comprising: detecting interference on resource elements of a serving cell OFDM symbol from a cell-specific reference signal (CRS) in an orthogonal frequency division multiplexing (OFDM) symbol of a neighboring cell; extracting the resource elements; constructing the CRS by compensating for the phase difference between the serving cell OFDM symbol and the neighboring cell OFDM symbol; and eliminating the interference in the resource elements based on the constructed CRS.

[0127] Example 10 includes the method of Example 9, wherein constructing the CRS includes: descrambling the CRS and performing frequency filtering.

[0128] Example 11 includes the method of Example 9, wherein constructing the CRS includes: performing a time-compensated filter to compensate for the phase difference.

[0129] Example 12 includes the method of Example 11, wherein performing time filtering includes: performing Kalman forward time filtering to rotate the phase of the neighboring cell OFDM symbol to the reference OFDM symbol; and performing Kalman backward time filtering to rotate the phase of the neighboring cell back to the original phase.

[0130] Example 13 includes the method of Example 11, wherein performing time filtering includes: performing Kalman forward time filtering to rotate the phase of the neighboring cell OFDM symbol to the reference OFDM symbol; and performing Kalman backward time filtering to rotate the phase of the neighboring cell back to the original phase.

[0131] Example 14 includes the method of Example 9, and further includes: receiving a list of neighboring cells from a base station; identifying the cell identifiers of neighboring cells based on the list of neighboring cells; and deriving the CRS shift based on the cell identifiers.

[0132] Example 15 includes the method of Example 9, wherein extracting resource elements includes: extracting resource elements based on the DC subcarrier of the serving cell.

[0133] Example 16 includes the method of Example 15, wherein extracting resource elements further includes: identifying extraction patterns for first, second, and third regions comprising the carrier bandwidth of the serving cell, the first region comprising a first resource block (RB) containing a DC subcarrier, the second region comprising one or more RBs at frequencies below the first RB, and the third region comprising one or more RBs at frequencies above the first RB.

[0134] Example 17 includes the method of Example 16, wherein extracting resource elements further includes: mapping CRS resource elements (REs) from neighboring cells to corresponding REs in a second region; and mapping CRS REs to REs offset by 1 from corresponding REs in a third region.

[0135] Example 18 includes a method for operating a user equipment (UE), the method comprising: extracting a first cell-specific reference signal (CRS) symbol based on a serving cell's direct current (DC) subcarrier; extracting a second CRS symbol based on the DC subcarrier; and determining a frequency offset estimate between the UE and an evolved Node B (eNB), the eNB transmitting the CRS received on the first and second CRS symbols.

[0136] Example 19 includes the method of Example 18, which further includes: determining a phase offset caused by the difference in generating Long Term Evolution (LTE) symbols and New Radio (NR) symbols; and generating an updated frequency offset estimate by excluding the phase offset from the frequency offset estimate.

[0137] Example 20 includes the method of Example 19, and further includes: constructing a CRS signal based on an updated frequency offset estimate; and removing interference from the signal of the serving cell based on the CRS signal.

[0138] Example 21 may include an apparatus comprising one or more elements for performing the method or any other method or process described herein, as described in or associated with any of Examples 1 to 20.

[0139] Example 22 may include one or more non-transitory computer-readable media, the one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of the method or any other method or process described herein, as described or associated with any of Examples 1 to 20.

[0140] Example 23 may include an apparatus comprising logic components, modules, or circuitry for performing one or more elements of the method described or associated with any of Examples 1 to 20 or any other method or process described herein.

[0141] Example 24 may include a method, technique, or process, or a part or component thereof, described or associated with any of Examples 1 to 20.

[0142] Example 25 may include an apparatus comprising one or more processors and one or more computer-readable media, the one or more computer-readable media including instructions that, when executed by the one or more processors, cause the one or more processors to perform a method, technique, or process, or a portion thereof, as described or associated with any of Examples 1 to 20.

[0143] Example 26 may include a signal, or a portion thereof, described or associated with any of Examples 1 to 20.

[0144] Example 27 may include a datagram, information element, packet, frame, segment, PDU or message, or a portion or component thereof, as described or associated with any of Examples 1 to 20, or otherwise described in this disclosure.

[0145] Example 28 may include a signal encoded with data according to or associated with any of Examples 1 to 20, or a portion or component thereof, or otherwise described in this disclosure.

[0146] Example 29 may include a signal, or a portion or component thereof, encoded as a datagram, IE, packet, frame, segment, PDU, or message, as described or associated with any of Examples 1 to 20, or otherwise described in this disclosure.

[0147] Example 30 may include an electromagnetic signal carrying computer-readable instructions, wherein execution of the computer-readable instructions by one or more processors will cause the one or more processors to perform a method, technique, or process, or a portion thereof, as described or associated with any of Examples 1 to 20.

[0148] Example 31 may include a computer program comprising instructions, wherein execution of the program by a processing element will cause the processing element to perform, or in part with, the methods, techniques or processes described or associated with any of Examples 1 to 20.

[0149] Example 32 may include signals in a wireless network as shown and described herein.

[0150] Example 33 may include methods for communicating in a wireless network as shown and described herein.

[0151] Example 34 may include a system for providing wireless communication as shown and described herein.

[0152] Example 35 may include a device for providing wireless communication as shown and described herein.

[0153] Unless otherwise expressly stated, any of the examples above may be combined with any other example (or combination of examples). The foregoing description of one or more specific embodiments provides illustration and description, but is not intended to be exhaustive or to limit the scope of the aspects to the precise form disclosed. In view of the teachings above, modifications and variations are possible, or can be derived from practice in various aspects.

[0154] Although the foregoing aspects have been described in considerable detail, many variations and modifications will become apparent to those skilled in the art once the foregoing disclosure is fully understood. This disclosure is intended to render the following claims as encompassing all such variations and modifications.

Claims

1. One or more computer-readable media CRMs, said CRMs having instructions that, when executed, cause a device to perform the following operations: Identify the cell identifiers of neighboring cells that transmit Cell-Specific Reference Signals (CRS); CRS shift is derived based on the cell identifier; The CRS is extracted based on the CRS shift and the DC subcarrier of the serving cell; Perform channel estimation for the CRS; as well as Based on the channel estimation, CRS interference is eliminated from the data received in the serving cell; In order to extract the CRS, the device is used for: Identify extraction patterns for a first region, a second region, and a third region that include the carrier bandwidth of the serving cell. The first region includes a first resource block (RB) containing the DC subcarrier, the second region includes one or more RBs at frequencies lower than the first RB, and the third region includes one or more RBs at frequencies higher than the first RB.

2. One or more CRMs according to claim 1, wherein the instruction, when executed, further causes the device to: The data is written to the Orthogonal Frequency Division Multiplexing (OFDM) symbol buffer based on the extraction mode.

3. One or more CRMs according to claim 1, wherein, in order to extract the CRS, the device is used to: Mapping CRS resource elements (REs) from the neighboring cells to the corresponding REs in the second region; and Map the CRS RE to a RE that is offset by 1 from the corresponding RE in the third region.

4. One or more CRMs according to claim 3, wherein the instruction, when executed, further causes the device to: It is determined that the first CRS RE will be mapped to a first RE outside the carrier bandwidth; A pseudo-reference signal is generated based on the first CRS RE; and The channel estimation is then performed based on the pseudo-reference signal.

5. One or more CRMs according to claim 1, wherein, in order to extract the CRS, the device is used to: Identify a first RE in the first region with a frequency lower than that of the DC subcarrier; Identify a second RE in the first region with a frequency higher than that of the DC subcarrier; Map the CRS REs from the neighboring cells to the corresponding REs of the first RE; and The CRS RE from the neighboring cell is mapped to a RE that is offset by 1 from the corresponding RE of the second RE.

6. One or more CRMs according to claim 1, wherein, in order to derive the CRS shift, the device is configured to: The CRS shift is determined to be equal to the cell identifier modulo 6.

7. One or more CRMs according to any one of claims 1 to 6, wherein the carrier bandwidth of the serving cell is greater than the carrier bandwidth of the adjacent cell.

8. A method for wireless communication, comprising: Interference is detected in the resource elements of the OFDM symbol of the serving cell from the cell-specific reference signal (CRS) in the OFDM symbol of the adjacent cell. Extract the resource elements; CRS is constructed by compensating for the phase difference between the OFDM symbols of the serving cell and the OFDM symbols of neighboring cells. as well as The CRS is constructed to eliminate interference in the resource elements; The extraction of the resource elements includes: Extraction patterns are identified for a first region, a second region, and a third region comprising the carrier bandwidth of the serving cell. The first region includes a first resource block (RB) containing a DC subcarrier of the serving cell. The second region includes one or more RBs at frequencies lower than the first RB. The third region includes one or more RBs at frequencies higher than the first RB.

9. The method of claim 8, wherein constructing the CRS comprises: Descramble the CRS and perform frequency filtering.

10. The method of claim 8, wherein constructing the CRS comprises: Perform time filtering with phase compensation to compensate for the phase difference.

11. The method of claim 10, wherein performing time filtering comprises: Perform Kalman forward time filtering to rotate the phase of the neighboring cell OFDM symbols to the reference OFDM symbol.

12. The method of claim 11, wherein performing time filtering further comprises: Perform Kalman inverse time filtering to rotate the phase of the neighboring cell OFDM symbols back to the original phase.

13. The method of claim 8, further comprising: Receive a list of neighboring cells from the base station; Identify the cell identifiers of neighboring cells based on the neighboring cell list; as well as The CRS shift is derived based on the cell identifier.

14. The method of claim 8, wherein extracting the resource element further comprises: Map the CRS resource elements (REs) from neighboring cells to the corresponding REs in the second region; And map the CRS RE to the RE offset by 1 from the corresponding RE in the third region.

15. A user equipment (UE), the UE including circuitry for performing the following operations: Extraction of the first cell-specific reference signal CRS symbol based on the serving cell's DC subcarrier; Extract the second CRS symbol based on the DC subcarrier; and Determine the frequency offset estimate between the UE and the evolved Node B (eNB), wherein the eNB transmits the CRS received on the first CRS symbol and the second CRS symbol; In order to extract the first CRS symbol and the second CRS symbol, the circuit is used for: Extraction patterns are identified for a first region, a second region, and a third region that include the carrier bandwidth of the serving cell. The first region includes a first resource block (RB) containing a DC subcarrier of the serving cell. The second region includes one or more RBs at frequencies lower than the first RB. The third region includes one or more RBs at frequencies higher than the first RB.

16. The UE of claim 15, wherein the circuitry is further configured to: Determine the phase shift caused by the difference between generating LTE symbols and NR symbols; and An updated frequency offset estimate is generated by excluding the phase offset from the frequency offset estimate.

17. The UE of claim 16, wherein the circuitry is further configured to: The CRS signal is constructed based on the updated frequency offset estimate; and The interference is removed from the signal of the serving cell based on the CRS signal.

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