Along with rapid development of wireless communication technology, NAICS technology is proposed in 3rd Generation Partnership Project (3GPP) Release 12 (R12), and its principle is that User Equipment (UE) configures an advanced receiver, and combines Interference Cancellation (IC) information notified by a network side and its own blind detection to effectively cancel interference and improve receiving performance.
An advanced receiver includes linear Enhanced Linear Minimum Mean Square Error-Interference Rejection Combining (E-LMMSE-IRC), and nonlinear Symbol-level Interference Cancellation (SLIC), Maximum Likelihood (ML) or Reduced complexity ML (R-ML), Code word level SIC (CWIC) and the like. The E-LMMSE-IRC estimates an interference channel by virtue of an interference cell pilot configuration and precoding matrix obtained from a high layer, and further performs interference rejection combining to improve receiving performance; and a nonlinear receiver estimates and reconstructs an interference signal by virtue of interference related information, and deletes the interference signal from the received signal to greatly improve receiving performance.
In order to implement effective IC, IC information required to be acquired by UE is shown in Table 1 as follows.
TABLE 1IC information typeIC information nameNetwork configurationSystem bandwidth, synchronization indicationrelatedCell-level andCell Identifier (ID), Common Reference Signalquasi-static(CRS) port, Multicast Broadcast SingleFrequency Network (MBSFN) configuration,downlink power allocation parameter PBUE-level andDownlink power allocation parameter PA,quasi-statictransmission mode, Channel State IndicationReference Signal (CSI-RS) configuration andQuasi Collocation (QCL)Cell-level and dynamicControl Format Indicator (CFI)UE-level and dynamicModulation order, preceding codebookindication, rank indication, DemodulationReference Signal (DMRS) port, resourceallocation granularity and type, and DMRSVirtual Cell ID (VCID)
At present, an acquisition manner for the IC information is being discussed by a 3GPP R12 standard: high-layer signalling notification or UE blind detection. The high-layer signalling notification manner may reduce complexity of blind detection and improve accuracy. However, for a user-level dynamic parameter, both timeliness and overhead of high-layer signalling notification are limited, and the blind detection manner is indispensable. According to five types of the IC information, the signalling design principle is that:
cell related and quasi-static IC information (an interference cell ID, a CRS port number, an MBSFN format and the like) with relatively lower signalling overhead is notified to UE by adopting high-layer signalling;
user-related dynamic IC information (a modulation order, a DMRS port number and the like) with acceptable blind detection complexity is acquired by virtue of UE blind detection; and
complexity of user related dynamic IC information (such as PA, a DMRS VOID and the like) with high blind detection complexity may be reduced in a manner of setting a subset.
However, for a Carrier Aggregation (CA) scenario, if UE performs NAICS on all Component Carriers (CCs) for CA, a great challenge may be brought to processing complexity of the UE. In a conventional art, for a scenario combining CA and NAICS, there is yet no solution to how to reduce the processing complexity of the UE.
USPTO Backgrounds
USPTO Backgrounds