摘要:
A method, an apparatus, and a computer program product for wireless communication are provided in which a system timing is estimated, derived from timing of one or more cells, a timing offset is determined for a plurality of cells relative to the estimated system timing, and signals received form the plurality of cells are processed using the timing offsets. In addition, a method, an apparatus, and a computer program product for wireless communication are provided in which a carrier frequency is estimated, derived from a frequency of one or more cells, a frequency offset is determined for a plurality of cells relative to the estimated system timing, and signals received form the plurality of cells are processed using the frequency offsets.
摘要:
Communications by base stations in wireless communication networks may be coordinated in a manner to improve performance by mobile devices experiencing interference from non-serving base stations. In particular, base station communications may be coordinated to improve the performance of interference cancellation by mobile devices. If a user equipment (UE) experiencing interference is capable of interference cancellation, then the base stations may coordinate to increase interference to that user equipment so as to improve that UE's ability to perform interference cancellation. Base stations may also coordinate to reduce interference for a UE, regardless of the UE's ability to perform interference cancellation. Mobile device performance improvements may also be achieved by coordinating scheduling of resources by the non-serving base stations, by using communication formats compatible with interference cancellation, by spatial coordination.
摘要:
Methods and apparatus for partitioning resources for enhanced inter-cell interference coordination (eICIC) are provided. Certain aspects involve broadcasting a message indicating time-domain resource partitioning information (RPI), where a user equipment (UE) may be operating in idle mode. With the RPI, the UE may be able to identify protected resources with reduced/eliminated interference from neighboring cells. The RPI in this broadcasted message may be encoded as a bitmap as an alternative or in addition to enumeration of the U/N/X subframes. Other aspects entail transmitting a dedicated or unicast message indicating the time-domain RPI, where a UE may be operating in connected mode. With the RPI, the UE may be able to determine channel state information (CSI), make radio resource management (RRM) measurements, or perform radio link monitoring (RLM), based on one or more signals from a serving base station during the protected time-domain resources.
摘要:
Physical-Layer Cell Identifier (PCID) collisions may occur in a wireless network when two neighboring evolved Node Bs (eNBs) having different Global Cell Identifiers (GCID) select identical PCIDs. Evolved Node Bs may uniquely identify themselves by transmitting on a broadcast channel, such as a Physical Broadcast Channel (PBCH), a pattern of bits corresponding to the eNB's GCID. Individual User Equipments (UEs) may recognize the PCID collision by decoding the PBCH payload to identify different GCID-modulated payloads from two eNBs involved in the PCID collision. Alternatively, UEs may detect PCID collisions in the wireless network by monitoring Primary Synchronization Signals (PSS) and Secondary Synchronization Signals (SSS) on the PBCH for identical signals separated by a relatively large time offset. After detecting a PCID collision, the UEs may attempt by best effort to report the PCID collision, may report to a fallback eNB, or the UEs may use special resources on an uplink channel.
摘要:
Aspects of the disclosure are related to identifying whether an apparatus (e.g., base station, access point, etc.) is transmitting using a CRS based transmission scheme or a UE-RS based transmission scheme. Such detection may be necessary for PDSCH interference cancellation (IC) of a neighboring cell since a UE may not know which transmission scheme is used by the neighboring cell. For instance, the UE may know the transmission scheme of the serving cell, but the UE may not know the transmission scheme of a neighboring non-serving cell. As such, aspects of the disclosure provide for a blind detection algorithm to identify or determine a transmission mode or transmission scheme of a neighboring cell to then apply interference cancellation (IC) to an interfering signal received from the neighboring cell.
摘要:
According to certain aspects, resource blocks used for physical downlink shared channel (PDSCH) transmissions may be allocated in a manner to manage interference in neighboring cells. According to certain aspects, one or more guard RBs may be utilized when transmitting PDSCH in a first cell an effort to reduce interference by transmissions in a second cell.
摘要:
In a wireless communication system, interference on data tones is estimated by detecting data transmissions from interferers. An overall interference covariance matrix is estimated as a function of scalar traffic to pilot ratio (TPR) estimates, residual interference covariance estimates, and covariance of channel estimates of dominant interferers. The interference estimates are refined as a function of reliability based on a ratio of power received from a serving cell and power received from a dominant interferer.
摘要:
Methods and apparatus for selecting samples for secondary synchronization signal (SSS) detection are described. Several alternatives are provided for efficient cell identifier detection. In a first alternative, multiple bursts of a signal received from a cell are sampled with non-uniform spacing between sampling intervals to determine a sequence for cell identification. In a second alternative, samples of a first and a second signal received from a stronger cell are cancelled, and a sequence for detecting a weaker cell is determined by reducing effects of the samples of a third signal received from the weaker cell which do not overlap with the primary synchronization signal (PSS) or SSS of the stronger cell. In a third alternative, a sequence for detecting a weaker cell is determined by reducing effects of any sampled bursts that correspond to a high transmission power portion of a signal from a stronger cell.
摘要:
Communication in a dominant interference scenario may be supported by performing inter-cell interference coordination (ICIC). According to certain aspects of ICIC, resource coordination/partitioning may be performed to allocate resources to a serving Node B located near the vicinity of a strong interfering Node B. The interfering Node B may avoid transmitting on the allocated/protected resources, but transmissions from the interfering Node B on resources not allocated to the serving Node B (i.e., unprotected) may cause significant interference on cell-specific reference signal (CRS) tones of the serving Node B. Therefore, if the CRS tones of the unallocated/unprotected resources are used, performance degradation may result to various operations of the serving Node B. Therefore, certain aspects of the present disclosure provide techniques for a UE receiver in utilizing resource partitioning information (RPI) for performing CRS processing in a heterogeneous network (HetNet).
摘要:
Methods and apparatus for selecting samples for secondary synchronization signal (SSS) detection are described. Several alternatives are provided for efficient cell identifier detection. In a first alternative, multiple bursts of a signal received from a cell are sampled with non-uniform spacing between sampling intervals to determine a sequence for cell identification. In a second alternative, samples of a first and a second signal received from a stronger cell are cancelled, and a sequence for detecting a weaker cell is determined by reducing effects of the samples of a third signal received from the weaker cell which do not overlap with the primary synchronization signal (PSS) or SSS of the stronger cell. In a third alternative, a sequence for detecting a weaker cell is determined by reducing effects of any sampled bursts that correspond to a high transmission power portion of a signal from a stronger cell.