Method and device for interference cancellation in new radio system

Abstract

A method of performing beam management (BM) and / or synchronization (Sync) by interference cancellation on synchronization signal block (SSB) is proposed. A UE determines an interference level and / or a pilot contamination level. Then, the UE can perform BM or synchronization with or without interference cancellation to accommodate the determined interference and pilot contamination levels. If the interference level is high, the UE applies interference cancellation for BM and Sync. If the interference level is low, the UE does not apply interference cancellation for BM and Sync. If the pilot contamination level is high, the UE follows a 3-symbol pattern, e.g., using only PBCH0, SSS, and PBCH2 symbols for BM or synchronization. If the pilot contamination level is low, the UE follows a 4-symbol pattern, e.g., using PSS as an additional symbol for BM or Sync to improve system performance.

Description

[0001] Cross-references This application claims priority to U.S. Provisional Patent Application No. 63 / 296,894, filed on August 19, 2021, entitled “Interference Cancellation Approach for New Radio Systems,” which is incorporated herein by reference in its entirety. Technical Field

[0002] The disclosed embodiments generally relate to wireless communication, and more specifically to interference cancellation in 5G New Radio (NR) cellular communication networks. Background Technology

[0003] Over the years, wireless communication networks have grown exponentially. Long Term Evolution (LTE) systems offer high peak data rates, low latency, improved system capacity, and low operating costs due to a simplified network architecture. LTE systems, also known as 4G systems, also provide seamless integration with legacy wireless networks such as GSM, CDMA, and Universal Mobile Telecommunications System (UMTS). In LTE systems, the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) comprises multiple evolved Node-Bs (eNodeBs or eNBs) that communicate with multiple mobile stations (called User Equipment (UEs)). 3GPP networks typically consist of a hybrid of 2G / 3G / 4G systems. The Next Generation Mobile Networks (NGMN) Committee has decided to focus future NGMN activities on defining the end-to-end requirements for 5G New Radio (NR) systems. In 5G NR, base stations are also called gNodeBs or gNBs.

[0004] 5G NR frequency bands are divided into two distinct frequency ranges. Frequency range 1 (FR1) includes bands below 6 GHz, some of which are traditionally used in previous standards but have been expanded to cover potential new spectrum offerings from 410 MHz to 7125 MHz. Frequency range 2 (FR2) includes bands from 24.25 GHz to 71.0 GHz. Within this millimeter-wave (mmWave) range, bands in FR2 have shorter propagation ranges than those in FR1, but offer higher available bandwidth. To compensate for the high propagation loss in 5G mmWave systems, UEs are typically equipped with multiple antennas for beamforming. For downlink data reception, UEs require beam management (BM), synchronization (time and frequency), and accurate Layer 1 (L1) measurements of the reference signal.

[0005] Similar to LTE, in 5G NR, the primary synchronization signal (PSS) and secondary synchronization signal (SSS) represent the Physical Cell Identifier (PCI), and the Physical Broadcast Channel (PBCH) carries the master information block (MIB). The SS block (SSB) in 5G NR represents the synchronization signal block, referencing both the PSS / SSS and PBCH blocks, as they are packaged together. The SSB is transmitted periodically, with each SSB burst containing both the PSS / SSS and PBCH. Specifically, the SSB with four OFDM symbols (PSS, PBCH0, SSS, PBCH2) serves as a good reference signal for beam management (BM) and synchronization at the UE. In scenarios with dense gNB distribution, the UE may suffer from neighboring cell interference on the serving cell's SSB and pilot pollution on the PSS, potentially degrading the performance of BM and synchronization. Mitigating interference with SSB, where necessary and feasible, can improve the performance of BM and Sync. Summary of the Invention

[0006] A method for performing beam management (BM) and / or synchronization and interference cancellation on a synchronization signal block (SSB) is proposed. The UE determines the interference level and / or pilot contamination level. The UE can then perform BM or synchronization, with or without interference cancellation, depending on the determined interference and pilot contamination levels. If the interference level is high, the UE applies interference cancellation to BM and Sync. If the interference level is low, the UE does not apply interference cancellation to BM and Sync. If the pilot contamination level is high, the UE follows a 3-symbol pattern, for example, using only the symbols PBCH0, SSS, and PBCH2 for BM or synchronization. If the pilot contamination level is low, the UE follows a 4-symbol pattern, for example, using PSS as an additional symbol for BM or Sync to improve system performance.

[0007] In one embodiment, the UE monitors synchronization signal block (SSB) transmissions from the serving cell and neighboring cells in the mobile communication network, where each SSB transmission includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). The UE determines the serving cell interference level based on the received SSBs. When the interference level is below a threshold, the UE performs beam management (BM) or synchronization without interference cancellation. When the serving cell interference level is above or equal to the threshold, the UE performs BM or synchronization with interference cancellation.

[0008] Other embodiments and advantages are described in the detailed description below. This overview is not intended to define the invention. Attached Figure Description

[0009] The accompanying drawings illustrate embodiments of the present invention, wherein the same numbers denote the same components.

[0010] Figure 1 An exemplary 5G New Radio (NR) network is illustrated, wherein the UE uses a Synchronization Signal Block (SSB) according to aspects of the invention to support adaptive interference cancellation for beam management (BM) and synchronization (Sync).

[0011] Figure 2 A simplified block diagram of a wireless device, such as a UE and a gNB, according to an embodiment of the present invention is shown.

[0012] Figure 3 The first embodiment of adaptive interference cancellation for BM and Sync is described, in which the UE first determines the interference level on the serving cell SSB and then determines the pilot pollution on the PSS.

[0013] Figure 4 The illustration shows a second embodiment of adaptive interference cancellation for BM and Sync, in which the UE first determines pilot pollution on the PSS and then determines the interference level on the serving cell SSB.

[0014] Figure 5 The diagram illustrates a state machine maintained by the UE for adaptively performing interference cancellation based on predetermined conditions.

[0015] Figure 6 An embodiment of interference level detection and determining the order of interference elimination based on predetermined conditions is illustrated.

[0016] Figure 7 This is a flowchart of a first method for performing adaptive interference cancellation on BM and Sync according to a novel aspect. Detailed Implementation

[0017] Reference will now be made in detail to some embodiments of the invention, examples of which are shown in the accompanying drawings.

[0018] Figure 1 An exemplary 5G New Radio (NR) network 100 according to the present invention includes user equipment (UE) supporting adaptive interference cancellation for beam management (BM) and synchronization (Sync) using the same synchronization signal block (SSB). The 5G NR network 100 includes user equipment (UE) 101 and multiple base stations, including a serving base station gNB 102. UE 101 is communicatively connected to the serving gNB 102, which provides radio access (e.g., 5G NR technology) using radio access technology (RAT). UE 101 may be a smartphone, wearable device, Internet of Things (IoT) device, tablet, etc. Optionally, UE 101 may be a laptop (NB) or personal computer (PC) with a data card inserted or installed, including a modem and RF transceiver to provide wireless communication capabilities. To compensate for the high propagation loss in 5G millimeter-wave systems, UEs are typically equipped with multiple antennas to achieve beamforming. For downlink (DL) data reception, the UE requires accurate L1 measurements of beam management (BM), synchronization (time and frequency), and reference signals.

[0019] Similar to LTE, in 5G NR, the Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS) represent the Physical Cell Identifier (PCI), and the Physical Broadcast Channel (PBCH) carries the Master Information Block (MIB). The SS Block (SSB) in 5G NR represents the Synchronization Signal Block, which refers to the synchronization signal (PSS / SSS) and PBCH block, as the synchronization signal and PBCH channel are packaged into a single block. The SSB is transmitted periodically, and each SSB burst contains the PSS / SSS and PBCH. Specifically, an SSB with four OFDM symbols (PSS, PBCH0, SSS, PBCH2) is a good reference signal for the UE to perform BM and Sync. In scenarios with dense gNB distribution, the UE may suffer from neighboring cell interference on the serving cell's SSB and pilot pollution on the PSS, thus potentially degrading BM and Sync performance. Mitigating SSB interference where necessary and feasible can improve BM and Sync performance.

[0020] According to a novel aspect, to improve system performance, a method is proposed that adaptively performs interference cancellation for beam management (BM) and synchronization (Sync) based on the interference level on the serving cell SSB and the pollution level on the PSS. Figure 1 In the example, UE 101 first determines the interference level (step 111) and / or the pilot contamination level (step 121). UE 101 can then perform BM or Sync with or without interference cancellation, depending on the determined interference and pilot contamination levels. If the interference level is high, UE 101 applies interference cancellation to BM and Sync (112). If the interference level is low, UE 101 does not apply interference cancellation to BM and Sync (113). If the pilot contamination level is high, UE 101 follows a 3-symbol pattern, for example, using only the symbols PBCH0, SSS, and PBCH2 for BM or Sync (122). If the pilot contamination level is low, UE 101 follows a 4-symbol pattern (123), for example, using PSS as an additional symbol for BM or Sync to improve system performance.

[0021] Figure 2 A simplified block diagram of a wireless device, such as a UE 201 and gNB 211 according to an embodiment of the present invention in a 5G NR network 200, is shown. gNB 211 has an antenna 215 that transmits and receives radio signals. An RF transceiver module 214, coupled to the antenna 215, receives the RF signals from the antenna 215, converts them into baseband signals, and sends them to a processor 213. RF transceiver 214 also converts the baseband signals received from the processor 213, converts them into RF signals, and sends them to the antenna 215. The processor 213 processes the received baseband signals and invokes different functional modules to perform features in gNB 211. Memory 212 stores program instructions and data 220 to control the operation of gNB 211. Figure 2 In the example, gNB211 also includes a protocol stack 280 and a set of control function modules and circuits 290. Protocol stack 280 may include a Non-Access Stratum (NAS) layer for communicating with the AMF / SMF / connecting to the core network MME entity, a Radio Resource Control (RRC) layer for higher-layer configuration and control, a Packet Data Convergence Protocol / Radio Link Control (PDCP / RRC) layer, a Media Access Control (MAC) layer, and a Physical (PHY) layer. In one example, control function modules and circuits 290 include configuration / control circuitry 291 for configuring measurement reports and activation sets for the UE, and handover processing circuitry, i.e., scheduling circuitry 292, for sending cell handover to the UE upon handover decision.

[0022] Similarly, UE 201 has memory 202, processor 203, and RF transceiver 204. RF transceiver 204 is coupled to antenna 205, receives RF signals from antenna 205, converts them into baseband signals, and sends them to processor 203. RF transceiver 204 also converts the received baseband signals from processor 203 into RF signals and sends them to antenna 205. Processor 203 processes the received baseband signals, calling different functional modules and circuits to execute features in UE 201. Memory 202 stores data and program instructions 210 to be executed by processor 203 to control the operation of UE 201. Suitable processors include, for example, dedicated processors, digital signal processors (DSPs), multiple microprocessors, one or more microprocessors associated with a DSP core, controllers, microcontrollers, application-specific integrated circuits (ASICs), file program gate arrays (FPGAs), and other types of integrated circuits (ICs) and / or state machines. The processor associated with the software can be used to implement and configure features of UE 201.

[0023] UE 201 also includes a protocol stack 260 and a set of control function modules and circuits 270. Protocol stack 260 may include a NAS layer for communicating with AMF / SMF / MME entities connected to the core network, an RRC layer for higher-level configuration and control, a PDCP / RLC layer, a MAC layer, and a PHY layer. Control function modules and circuits 270 may be implemented and configured in software, infrastructure, hardware, and / or combinations thereof. Control function modules and circuits 270 cooperate with each other when executed by processor 203 via program instructions contained in memory 202 to allow UE 201 to perform implementations and functional tasks and features within the network. In one example, control function modules and circuits 270 include configuration / control circuitry 271 for acquiring measurement and configuration information and controlling corresponding operations, interference cancellation circuitry 272 for performing interference detection and cancellation, beam management (BM) circuitry 273 for performing DL and UL beam management, and synchronization processing circuitry (Sync) 274 for performing synchronization functions based on configuration received from the network.

[0024] Interference and pilot pollution on the serving cell's SSB are issues to consider when performing BM and Sync. As mentioned above, the SSB consists of synchronization signals (PSS, SSS) and PBCH. The synchronization signals are used for cell ID detection and synchronization. Furthermore, 5G NR uses a beam management (BM) procedure to acquire and maintain a set of beams to ensure gNB and UE beam alignment for data communication. Specifically, four OFDM symbols (PSS, PBCH0, SSS, PBCH2) are encapsulated in the SSB, allowing the UE to use all or some of them for BM and Sync. Each base station and serving / neighboring cell generates its own SSB based on the physical cell ID (NID(cell)) and SSB index. There is a correlation between the SSB transmissions of the serving base station and neighboring base stations in the serving cell and neighboring cells. This correlation varies depending on the network deployment.

[0025] For PSS generation, the PSS value depends on the sector cell ID. Therefore, PSS has only three sequences to choose from; for SSS generation, the order of SSS depends on the composite cell ID. Therefore, there are 336 sequences available for the SSS. For PBCH generation, the PBCH-DMRS sequence depends on the SSB index and the physical cell ID, where the SSB index determines its scrambling sequence and the physical cell ID determines its frequency location. Therefore, the level of pilot contamination on the PSS depends on the network deployment scenario. In denser network deployments, neighboring cells may use the same PSS as the serving cell. Therefore, the serving cell's PSS may suffer from pilot contamination. In contrast, in sparser deployments, neighboring and serving cells are likely to use different PSSs. When the serving cell's PSS is contaminated by neighboring cells, using the PSS for BM and Sync is unreliable. Conversely, if the serving cell's PSS is not contaminated with pilots, it can serve as an additional symbol for BM and Sync to improve performance.

[0026] Figure 3The illustration shows a first embodiment of adaptive interference cancellation for BM / Sync, where the UE first determines the interference level on the serving cell SSB and then determines pilot pollution on the PSS. In step 311, the UE determines the interference level on the serving cell SSB. In step 312, the UE checks whether the interference level is low, for example, whether the SIR is higher than a predefined threshold. If true, the UE performs BM / Sync without interference cancellation. Furthermore, the UE assumes that the pilot pollution on the PSS is also low and uses all 4-symbol SSBs for the BM / Sync procedure. If the answer to step 312 is false, the UE proceeds to step 321 and determines the pilot pollution level on the PSS. In step 322, the UE checks whether the pilot pollution level on the PSS is low, for example, below a predefined threshold. If true, the UE uses 4-symbol SSBs to perform BM / Sync with interference cancellation (step 323). If the answer to step 322 is no, the UE performs BM / Sync with interference cancellation using 3-symbol SSBs by skipping the PSS (step 324).

[0027] Figure 4 The illustration shows a second embodiment of adaptive interference cancellation for BM / Sync, where the UE first determines pilot pollution on the PSS and then determines the interference level on the serving cell SSB. In step 411, the UE determines the pilot pollution level on the PSS. In step 412, the UE checks whether the pilot pollution level on the PSS is low, for example, below a predefined threshold. If true, the UE performs BM / Sync without interference cancellation using a 4-symbol SSB (step 421). In step 422, the UE further determines the interference level on the serving cell SSB. In step 423, the UE checks whether the interference level is low, for example, whether the SIR is above a predefined threshold. If true, the UE returns to step 421 and performs BM / Sync without interference cancellation. If the answer to step 423 is no, the UE proceeds to step 424 and performs BM / Sync with interference cancellation using a 4-symbol SSB. Step 425 is an example of performing BM / Sync using all four SSB OFDM symbols.

[0028] If the answer to step 412 is no, the UE uses 3-symbol SSB to perform BM / Sync without interference cancellation (step 431). In step 432, the UE determines the interference level on the serving cell SSB. In step 433, the UE checks whether the interference level is low, for example, whether the SIR is higher than a predefined threshold. If yes, the UE returns to step 431 and performs BM / Sync without interference cancellation. If the answer to step 433 is no, the UE proceeds to step 434 and uses the 3-symbol SSB to perform BM / Sync with interference cancellation. Step 435 is an example of performing the BM / Sync of the process using three SSB OFDM symbols.

[0029] Figure 5 illustrates a state machine maintained by a UE for adaptively performing interference cancellation based on predetermined conditions. In Figure 5 the embodiment, two different methods are used to perform BM and Sync: without interference cancellation and with interference cancellation. In a novel aspect, a state machine is proposed to switch between the two BM and Sync methods with (after) and without (before) interference cancellation according to the detected signal-to-interference ratio (SIR). Two conditions are predefined for switching between the two BM and Sync methods. Condition-1 is defined as the SIR of the serving cell being lower than a predefined threshold: SIR_SC<SIR_Th; Condition-2 is defined as the SIR of the serving cell after interference cancellation being lower than the SIR of the serving cell without interference cancellation (before) plus a threshold: SIR_(SC, after)<SIR_(SC, before) +Th. If Condition-1 is satisfied, it indicates that the SIR of the serving cell is low, triggering the UE to apply interference cancellation; if Condition 2 is satisfied, it means that interference cancellation will not improve the SIR much. Then, the UE returns to the operation of performing BM and Sync without interference cancellation.

[0030] Figure 6 illustrates an embodiment of interference level detection and determining the interference cancellation order based on predefined conditions. The UE monitors SSB transmissions from the serving cell and neighboring cells. In step 611, the UE calculates the serving cell SIR_SC based on PBCH-DMRS or SSS. In one example, the serving cell SIR_SC is calculated as follows: total symbol power = estimated signal power + interference power + system noise power; interference power = total symbol power - estimated signal power - system noise power; SIR = estimated signal power / interference power. In step 612, the UE checks the serving cell SIR SCIs it less than a predetermined threshold? If false, it means the serving cell's SIR is high, and the UE can skip interference cancellation (step 613). If true, it means the serving cell's SIR is low, and the UE can apply interference cancellation. In step 621, the UE determines the RSRP based on the radio signal strength and quality of the serving cell and neighboring cells. SC SNR SC and RSRP NC SNR NC Determine the order in which interference is eliminated.

[0031] In step 622, the UE checks whether the RSRP or SNR difference between the serving cell and neighboring cells is greater than a threshold. If the answer is yes, the UE proceeds to step 623; otherwise, the UE proceeds to step 624. In step 623, the UE performs the following sub-steps: Step 1: Estimate the serving cell channel and reconstruct the serving cell signal; Step 2: Remove the serving cell signal from the received signal (received signal = serving cell signal + neighboring cell signal + system noise); Step 3: Estimate the neighboring cell channel and reconstruct the strongest neighboring cell signal based on the signal after Step 2; Step 4: Eliminate the strongest neighboring cell signal from the original received signal. In step 624, the UE performs the following sub-steps: Step 1: Estimate the neighboring cell channel and reconstruct the strongest neighboring cell signal; Step 2: Eliminate the neighboring cell signal from the received signal (received signal = serving cell signal + neighboring cell signal + system noise).

[0032] Figure 7 This is a flowchart of a first method for performing adaptive interference cancellation on beam management (BM) and synchronization (Sync) according to a novel aspect. In step 701, the UE monitors synchronization signal block (SSB) transmissions from the serving cell and neighboring cells in the mobile communication network, where each SSB transmission includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). In step 702, the UE determines the serving cell interference level based on the received SSBs. In step 703, when the interference level is below a threshold, the UE performs beam management (BM) or synchronization (Sync) without interference cancellation. In step 704, when the serving cell interference level is above or equal to the threshold, the UE performs BM or synchronization with interference cancellation.

[0033] Although the invention has been described in conjunction with specific embodiments for illustrative purposes, the invention is not limited thereto. Therefore, various modifications, adaptations, and combinations of the various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims.

Claims

1. An interference cancellation method, comprising: Monitor synchronization signal blocks sent by user equipment from serving cell and neighboring cells in a mobile communication network, wherein each synchronization signal block transmits a primary synchronization signal, an auxiliary synchronization signal, and a physical broadcast channel; The interference level of the serving cell is determined based on the received synchronization signal block; When the interference level is below a threshold, beam management or synchronization is performed without interference cancellation; and When the interference level of the serving cell is higher than or equal to the threshold, beam management or synchronization is performed in the event of interference cancellation.

2. The interference cancellation method according to claim 1, characterized in that, The interference level is determined by calculating the signal-to-interference ratio based on the received synchronization signal blocks of the serving cell.

3. The interference cancellation method according to claim 1, characterized in that, Also includes: Determine the pilot pollution level on the primary synchronization signal of the serving cell.

4. The interference cancellation method according to claim 3, characterized in that, When the pilot pollution level on the primary synchronization signal is higher than or equal to a predetermined threshold, the user equipment uses only the auxiliary synchronization signal and physical broadcast channel symbols to perform beam management or synchronization.

5. The interference cancellation method according to claim 3, characterized in that, When the pilot pollution level on the primary synchronization signal is below a threshold, the user equipment uses the primary synchronization signal, auxiliary synchronization signal, and physical broadcast channel symbols to perform beam management or synchronization.

6. The interference cancellation method according to claim 3, characterized in that, The user equipment determines the pilot pollution level on the primary synchronization signal before or after determining the serving cell interference level based on the received synchronization signal block.

7. The interference cancellation method according to claim 1, characterized in that, The user equipment maintenance is used to switch between performing beam management or synchronization with and without interference cancellation.

8. The interference cancellation method according to claim 7, characterized in that, When the interference level of the serving cell is not reduced to a predetermined threshold, the user equipment switches from performing beam management or synchronization with interference cancellation to performing beam management or synchronization without interference cancellation.

9. The interference cancellation method according to claim 1, characterized in that, The user equipment determines the order of interference cancellation based on the radio signal strength and quality of the serving cell and the neighboring cells.

10. The interference cancellation method according to claim 9, characterized in that, When the difference in radio signal strength or quality between the serving cell and the neighboring cell is greater than or equal to a predetermined threshold, the user equipment reconstructs the serving cell signal from the received signals, eliminates the serving cell signal from the received signals, then reconstructs the strongest neighboring cell signal, and then eliminates the strongest neighboring cell signal from the received signals.

11. The interference cancellation method according to claim 9, characterized in that, When the difference in wireless signal strength or quality between the serving cell and neighboring cells is less than or equal to a predetermined threshold, the user equipment reconstructs the strongest neighboring cell signal and then removes the strongest neighboring cell signal from the received signals.

12. An interference cancellation user equipment, comprising: A receiver that receives synchronization signal block transmissions from serving cells and neighboring cells in a mobile communication network, wherein each synchronization signal block transmission includes a primary synchronization signal, an auxiliary synchronization signal, and a physical broadcast channel; The control circuit determines the interference level of the serving cell based on the received synchronization signal block; and The beam management and synchronization circuit performs beam management or synchronization without interference cancellation when the interference level is below a threshold, and performs beam management or synchronization with interference cancellation when the interference level of the serving cell is higher than or equal to the threshold.

13. The interference cancellation user equipment according to claim 12, characterized in that, The interference level is determined by calculating the signal-to-interference ratio based on the received synchronization signal blocks of the serving cell.

14. The interference cancellation user equipment according to claim 12, characterized in that, Also includes: Determine the pilot pollution level on the primary synchronization signal of the serving cell.

15. The interference cancellation user equipment according to claim 14, characterized in that, When the pilot pollution level on the primary synchronization signal is higher than or equal to a predetermined threshold, the user equipment uses only the auxiliary synchronization signal and physical broadcast channel symbols to perform beam management or synchronization.

16. The interference cancellation user equipment according to claim 14, characterized in that, When the pilot pollution level on the primary synchronization signal is below a threshold, the user equipment uses the primary synchronization signal, the auxiliary synchronization signal, and the physical broadcast channel symbol to perform beam management or synchronization.

17. The interference cancellation user equipment according to claim 14, characterized in that, The user equipment determines the pilot pollution level on the primary synchronization signal before or after determining the serving cell interference level based on the received synchronization signal block.

18. The interference cancellation user equipment according to claim 12, characterized in that, The user equipment maintenance is used to switch between performing beam management or synchronization with and without interference cancellation.

19. The interference cancellation user equipment according to claim 18, characterized in that, When the interference level of the serving cell is not reduced to a predetermined threshold, the user equipment switches from performing beam management or synchronization with interference cancellation to performing beam management or synchronization without interference cancellation.

20. The interference cancellation user equipment according to claim 12, characterized in that, The user equipment determines the order of interference cancellation based on the radio signal strength and quality of the serving cell and neighboring cells.

21. The interference cancellation user equipment according to claim 20, characterized in that, When the difference in radio signal strength or quality between the serving cell and the neighboring cell is greater than a predetermined threshold, the user equipment reconstructs the serving cell signal from the received signals, eliminates the serving cell signal from the received signals, then reconstructs the strongest neighboring cell signal, and then eliminates the strongest neighboring cell signal from the received signals.

22. The interference cancellation user equipment according to claim 20, characterized in that, When the difference in radio signal strength or quality between the serving cell and the neighboring cell is less than or equal to a predetermined threshold, the user equipment reconstructs the strongest neighboring cell signal and then removes the strongest neighboring cell signal from the received signals.

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