Patent application number | Description | Published |
20080247364 | CYCLIC DELAY DIVERSITY AND PRECODING FOR WIRELESS COMMUNICATION - Techniques for sending a MIMO transmission using a combination of cyclic delay diversity and precoding are described. A set of delays (e.g., zero delay, small delay, and large delay) for cyclic delay diversity and a set of precoding matrices may be supported. In one design, a Node B may select a delay specifically for a UE or for a set of UEs served by the Node B. In another design, a UE may evaluate different combinations of precoding matrix and delay, determine the combination with the best performance, and send this combination of precoding matrix and delay to the Node B. The Node B may perform precoding with the precoding matrix and then processing for cyclic delay diversity based on the selected delay. Alternatively, the Node B may perform processing for cyclic delay diversity based on the selected delay and then precoding with the precoding matrix. | 10-09-2008 |
20080268834 | Method of grouping users to reduce interference in mimo-based wireless network - In a system of MIMO communications in a wireless network, a number of wireless units are logically divided into a plurality of user groups, through operation of a semi-orthogonal user selection sub-system. For example, the user selection sub-system may implement a heuristic user selection algorithm based on near-orthogonality. Each user group is assigned a discrete transmission channel, which may be orthogonally defined in terms of frequency, time, or code. Data is transmitted over the channels (e.g., from network base stations) in a coherently coordinated manner, according to a zero-forcing beamforming operation. The system may be configured for operation in a time/frequency selective manner, e.g., over time/frequency selective fading channels. The wireless units may be allocated to the time/frequency slots based on prioritization of channel strength and considerations of fairness, in conjunction with the application of a semi-orthogonal user selection algorithm. | 10-30-2008 |
20080287075 | TRANSPOSED STRUCTURE FOR CYCLIC DELAY DIVERSITY (CDD) BASED PRECODING - Systems and methodologies are described that facilitate applying cyclic delay diversity (CDD) and precoding to wireless transmissions. In particular, data vectors to be transmitted to a number of receive antennas of a receiver can be transformed to a virtual antenna domain. CDD can be applied to this domain followed by precoding to allow the benefits of precoding to remain though CDD is applied. In this regard, the resulting signals can be transmitted without pouring transmission energy into null spaces unreachable by receiving devices. | 11-20-2008 |
20100027697 | MIMO TRANSMISSION WITH LAYER PERMUTATION IN A WIRELESS COMMUNICATION SYSTEM - Techniques for supporting MIMO transmission with layer permutation are described. In one aspect, multiple codewords may be generated for transmission from multiple antennas (e.g., virtual antennas), with the number of codewords being less than the number of antennas. Each codeword may be mapped across the multiple antennas. Two codewords may be generated. For rank 3, the first codeword may be mapped to one layer (or one antenna on each subcarrier), and the second codeword may be mapped to two layers (or two antennas on each subcarrier). For rank 4, each codeword may be mapped to two layers. In another aspect, a base CQI indicative of an average signal quality may be determined. A delta CQI indicative of improvement over the average signal quality may also be determined. In yet another aspect, selection may be performed with different penalty factors for different ranks or number of codewords. | 02-04-2010 |
20100040179 | CHANNEL ESTIMATION - Aspects describe channel estimation in an OFDM system. Baseline DFT-based channel estimation can be performed and scaling can be applied to mitigate distortion in the DFT-based estimations. In some aspects, baseline DFT-based channel estimation can be performed and tones for which DFT-based estimate is deemed unreliable can have MMSE based processing applied locally. If orthogonal sequence is deemed excessive, orthogonal sequence cancellation can be applied prior to the MMSE based processing. | 02-18-2010 |
20100177653 | METHOD AND APPARATUS FOR COMPUTING AND REPORTING CHANNEL QUALITY INDICATION (CQI) - Techniques for computing and reporting channel quality indication (CQI) are described. In an aspect, a plurality of CQI computation methods may be supported, and each CQI computation method may indicate how CQI should be computed. One CQI computation method may be selected for use. CQI may then be computed and reported in accordance with the selected CQI computation method. In an exemplary design, a user equipment (UE) may obtain a selected method for computing CQI, which may be chosen based on the UE capability and/or other factors. The selected method may specify (i) CQI computation for a specific codeword among a plurality of codewords or (ii) CQI computation by averaging signal quality across a plurality of layers used for transmission. The UE may compute CQI in accordance with the selected method, send the CQI to a base station, and receive data sent by the base station based on the CQI. | 07-15-2010 |
20110026645 | SYSTEMS, APPARATUS AND METHODS FOR BROADCAST CHANNEL DECODING - Techniques for reliable channel decoding in a wireless network are provided. In one aspect, a wireless device receives system information over a physical broadcast channel of a downlink transmission. The wireless device decodes the physical broadcast channel of a current radio frame using a plurality of hypotheses until the decoding passes a cyclic redundancy check. Thereafter, the wireless device compares system information from the current radio frame with information obtained from a previous radio frame. The information from the previous radio frame may include one or more network parameters which may be stored in a memory of the wireless device. In some aspects, the comparison may be performed over a plurality of radio frames. Based at least in part on a result of the comparing, the wireless device may selectively reject system information from one or more of the radio frames. | 02-03-2011 |
20110092231 | TIME AND FREQUENCY ACQUISITION AND TRACKING FOR OFDMA WIRELESS SYSTEMS - Obtaining a timing reference in wireless communication is facilitated when desiring to communicate with a weak serving base station (such as an evolved NodeB) in the presence of a stronger interfering base station. The user equipment (UE) may track a stronger interfering base station's timing, or the UE may track a timing that is derived by a composite power delay profile (PDP) from multiple base stations. The composite PDP may be constructed by adjusting individual base station PDPs according to a weighting scheme. The timing obtained in such a manner may be used for estimation of the channel of the interfering base station and cancelling interfering signals from the base station. It may also be used to estimate the channel of the serving base station after adding a backoff. The UE may track a stronger interfering base station's frequency, or the UE may track a composite frequency. | 04-21-2011 |
20110116561 | MONITORING AND CORRECTING TIMING ERRORS IN WIRELESS COMMUNICATION - Providing for improved tracking and correction of timing in wireless communications is disclosed herein. By way of example, a first algorithm can be employed to track timing of a wireless signal, based on one dimension of the signal. Additionally, a second algorithm based on a different dimension of the signal can be employed to verify the timing and reduce errors in timing analysis. Various signal dimensions can be employed for the analysis, including cyclic prefix, frequency, channel impulse response, or the like, or a combination thereof. Additionally, different channels of the wireless signal can also be analyzed by the first algorithm and the second algorithm. Furthermore, the second algorithm can be selected to reduce deficiencies identified in the first algorithm, to improve overall timing analysis, reduce undetected timing errors or false errors, and improve timing correction. | 05-19-2011 |
20110129009 | METHOD AND SYSTEM FOR EFFICIENT CHANNEL ESTIMATION - Aspects of the present disclosure describe an efficient channel estimation algorithm for high-speed processing of dedicated reference signals. The channel estimation algorithm may utilize one or more compressed interpolation matrices. The compressed interpolation matrices may be selected based on the Doppler value and signal to noise ratio (SNR) of the channel. | 06-02-2011 |
20110141927 | PRECODING CONTROL CHANNELS IN WIRELESS NETWORKS - Systems and methodologies are described that facilitate precoding signals transmitted over downlink control channels to provide transmit diversity. A dedicated reference signal (DRS) related to a wireless device can additionally be precoded such that the wireless device can determine a precoder or related parameters based at least in part on performing a channel estimate for the precoded DRS signal. The wireless device can utilize the determined precoder or related parameters to decode precoded signals received over downlink control channel resources. Additionally or alternatively, an access point can signal a sequence of precoders to the wireless device. The access point can cycle through the sequence of precoders to precode signals for transmission over downlink control channel resources, and the wireless device can decode the signals based at least in part on similarly cycling through the precoders for received signals. | 06-16-2011 |
20110143672 | METHOD AND SYSTEMS FOR PARALLEL CHANNEL ESTIMATION AND INTERFERENCE CANCELLATION - Certain aspects of the disclosure propose parallel channel estimation and interference cancellation in a wireless communications system. For each common reference signal tone offset, interference cancellation and channel estimation may be performed independently. The proposed channel estimation method may increase performance of a system. | 06-16-2011 |
20110159914 | Interaction Between Accumulative Power Control And Minimum/Maximum Transmit Power In LTE Systems - Methods and apparatus in a wireless communication system are described for receiving and processing transmit power control commands, where, for example, the response to the transmit power control commands is conditionally decoupled from at least one of a transmit bandwidth parameter, a transport format parameter and a power stepsize limit. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the disclosed subject matter. Therefore, it is to be understood that it should not be used to interpret or limit the scope or the meaning of the claims. | 06-30-2011 |
20110182252 | NETWORK-ASSISTED CELL ACCESS - Providing for access point assisted signal acquisition for heterogeneous access point wireless networks is described herein. By way of example, a closed subscriber group (CSG) base station, such as a home NodeB (HNB) can be configured to provide temporary, limited access to a UE that is not authorized to access the HNB. Upon receiving and rejecting an access probe, the HNB can negotiate with a surrounding macro network to provide service for the UE. Further, the HNB can forward signal acquisition data, to assist in proper decoding of pilot or synchronization signals of the macro network. In particular aspects, the HNB can reduce power or blank transmissions on reserved access resources to reduce interference for the UE. By these and other disclosed mechanisms, the HNB can assist a non-CSG subscriber to obtain network service, and mitigate interference effects due to proximity to the UE. | 07-28-2011 |
20110188393 | REPORTING OF CHANNEL INFORMATION TO SUPPORT COORDINATED MULTI-POINT DATA TRANSMISSION - Techniques for reporting channel information are described. In one aspect, a plurality of channel information reporting modes are available to a user equipment (UE) for reporting channel information for coordinated multi-point (CoMP) data transmission. The UE may determine a first channel information reporting mode to use, determine first channel information related to at least one cell in a CoMP measurement set of the UE, and send the first channel information in accordance with the first channel information reporting mode to one or more cells in the CoMP measurement set. The UE may also determine a second channel information reporting mode to use, determine second channel information related to multiple cells in the CoMP measurement set, and send the second channel information in accordance with the second channel information reporting mode. A plurality of channel feedback configurations may be supported, including a single-stage, a two-stage, and/or a one-shot channel configurations. | 08-04-2011 |
20110188462 | METHOD AND APPARATUS FOR SIGNALING EXPANSION AND BACKWARD COMPATIBILITY PRESERVATION IN WIRELESS COMMUNICATION SYSTEMS - Certain aspects of the present disclosure provide for signaling to expanded capability UEs that may limit the interruption of legacy UEs. According to certain aspects, a base station (e.g., an eNB) may generate and transmit one or more signals containing information that is recognizable by at least one expanded capability UE and identified as invalid by at least one legacy UE. An expanded capability UE may receive such signaling and identifying supplemental information in the signaling, while a legacy UE may regard the signaling as invalid. | 08-04-2011 |
20110190024 | INTERFERENCE MITIGATION BY PUNCTURING TRANSMISSION OF INTERFERING CELLS - Systems and methodologies are described that facilitate controlling interference in a heterogeneous wireless communication environment. A Physical Broadcast Channel (PBCH) transmission from an interfering base station can be punctured based upon a puncturing pattern as a function of a cell identifier (ID) and a transmit time. Puncturing can be effectuated by applying power control. Thus, a punctured symbol or subframe can have a reduced transmit power or a transmit power set to zero. Further, the puncturing pattern can be defined on a subframe basis or on a symbol basis. | 08-04-2011 |
20110194430 | METHOD AND APPARATUS FOR UNIFIED CHANNEL ESTIMATION FOR WIRELESS COMMUNICATION - Certain aspects of the disclosure propose a unified channel estimation algorithm that combines two or more channel estimation algorithms in a single piece of hardware or software. The proposed unified channel estimation may dynamically switch, based on one or more metrics, between different modes of operation that utilize different channel estimation algorithms. | 08-11-2011 |
20110205982 | METHOD AND APPARATUS THAT FACILITATES DETECTING SYSTEM INFORMATION BLOCKS IN A HETEROGENEOUS NETWORK - Aspects are disclosed for detecting a system information block (SIB) within a heterogeneous network. In one aspect, a type of scheduling information pertaining to an SIB is selected, and a parameter known to a wireless terminal is associated with the type of scheduling information. The wireless terminal then decodes the SIB by deriving the scheduling information from the known parameters, without having to decode a Physical Downlink Control Channel. | 08-25-2011 |
20110216842 | TRANSMISSION OF UE-SPECIFIC REFERENCE SIGNAL FOR WIRELESS COMMUNICATION - Techniques for transmitting UE-specific reference signals (UE-RSs) in a wireless network are described. In an aspect, a UE-RS may be transmitted in different manners depending on the number of layers used for data transmission. In one design, a cell may determine subcarriers for a UE-RS based on a frequency shift if data is transmitted on one layer and based on a predetermined set of subcarriers (with no frequency shift) if data is transmitted on multiple layers. In another aspect, a UE-RS may be transmitted on subcarriers determined based on a frequency shift for data transmission on multiple layers. In yet another aspect, a UE-RS may be transmitted from a plurality of cells to a UE for coordinated multi-point (CoMP). In yet another aspect, a UE-RS may be transmitted in a data section of a subframe including only the data section. | 09-08-2011 |
20110235601 | PHYSICAL DOWNLINK SHARED CHANNEL (PDSCH) PROTECTION - 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. | 09-29-2011 |
20110250919 | CQI ESTIMATION IN A WIRELESS COMMUNICATION NETWORK - Techniques for estimating and reporting channel quality indicator (CQI) are disclosed. Neighboring base stations may cause strong interference to one another and may be allocated different resources, e.g., different subframes. A UE may observe different levels of interference on different resources. In an aspect, the UE may determine a CQI for resources allocated to a base station and having reduced or no interference from at least one interfering base station. In another aspect, the UE may determine multiple CQI for resources of different types and associated with different interference levels. For example, the UE may determine a first CQI based on at least one first subframe allocated to the base station and having reduced or no interference from the interfering base station(s). The UE may determine a second CQI based on at least one second subframe allocated to the interfering base station(s). | 10-13-2011 |
20110255486 | METHODS AND APPARATUS FOR CROSS-CELL COORDINATION AND SIGNALING - Methods and apparatus for providing cross-cell signaling and/or coordination for interference mitigation in wireless communication networks are described. In one aspect, a UE associated with a serving eNB may receive control signaling from another non-serving eNB in a different cell. The control signaling may be consistent with a characteristic of the serving eNB and associated cell. In another aspect, multiple eNBs may coordinate transmission of DL resources to minimize collisions of control signaling resources. | 10-20-2011 |
20110256861 | RADIO LINK MONITORING (RLM) AND REFERENCE SIGNAL RECEIVED POWER (RSRP) MEASUREMENT FOR HETEROGENEOUS NETWORKS - A method for communicating in an advanced long term evolution (LTE-A) network using common reference signal (CRS) resources associated with different interference levels due to resource partitioning is disclosed. Signals are received from an eNodeB indicating a subset of CRS resources for radio link monitoring (RLM) and/or reference signal received power (RSRP) measuring. The subset of CRS resources includes the CRS resources expected to have lower interference from the interfering eNodeBs. RLM and/or RSRP measurements are performed based on the indicated subset. | 10-20-2011 |
20110261673 | MODIFIED SPATIAL DIVERSITY SCHEMES FOR COVERAGE ENHANCEMENT - In one aspect, a method to enhance coverage in a heterogeneous wireless network wireless communication is disclosed. The method includes generating a reference signal indicating a plurality of transmit antenna ports and generating modulation symbols. Modulation symbols are assigned to each of the plurality of transmit antenna ports, in accordance with a spatial diversity coding scheme for the plurality of transmit antenna ports. At least one of the modulation symbols assigned to at least one of the plurality of transmit antenna ports is muted prior to transmission in accordance with the spatial diversity coding scheme. The non-muted modulation symbols and the reference signal are transmitted on the other of the plurality of transmit antenna ports. | 10-27-2011 |
20110267937 | INTERFERENCE CANCELLATION - A method to enhance coverage and/or throughput in a heterogeneous wireless network includes detecting interference between a neighboring cell and a serving cell. The method also includes cancelling the interference using an adaptive technique based on whether the interference has colliding Common Reference Signal (CRS) tones. | 11-03-2011 |
20110274097 | DETECTING AND REPORTING PHYSICAL-LAYER CELL IDENTIFIER COLLISIONS IN WIRELESS NETWORKS - 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. | 11-10-2011 |
20110275394 | RESOURCE PARTITIONING INFORMATION FOR ENHANCED INTERFERENCE COORDINATION - 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. | 11-10-2011 |
20110286376 | PER-CELL TIMING AND/OR FREQUENCY ACQUISITION AND THEIR USE ON CHANNEL ESTIMATION IN WIRELESS NETWORKS - 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. | 11-24-2011 |
20110292875 | APPARATUS AND METHOD FOR PHYSICAL BROADCAST CHANNEL (PBCH) DECODING FOR MULTIPLE CELLS - A method of wireless communication includes generating a list of cells for physical broadcast channel (PBCH) decoding. The method also includes allocating memory for decoding and cancelling a subset of cells from the generated cell list. The method further includes storing information related to subsets of cells from the generated list in the allocated memory during different time periods. The allocated memory is sufficient for attempting, at each time period, decoding of each subset of cells and cancelling of decoded cells in each subset. The method further includes cycling through the generated cell list by processing each subset of the cell list during the different time periods. | 12-01-2011 |
20110317624 | METHODS OF CONTROL/DATA PARTITION SCHEME IN HETEROGENEOUS NETWORKS FOR LTE-A - When there are different power classes of base stations (BSs), there may be a need to coordinate transmission from the different BSs to reduce interference to a user equipment (UE) on both control channels and data channels. There are different ways of coordination. For some embodiments, time division multiplex (TDM) resource partitioning may be performed across BSs on a subframe level. TDM resource partitioning may avoid control channel interference since resource mapping on time and frequency for control channels may span the whole frequency domain. However, the data rate for the UE may be limited due to the TDM partitioning of subframes. In other words, a limitation may derive from control channel interference coordination. For some embodiments, a UE may transmit and/or receive in subframes other than the ones partitioned for the UE. | 12-29-2011 |
20120008555 | TRANSMIT AND RECEIVE PROCESSING IN THE PRESENCE OF INTERFERENCE IN A WIRELESS NETWORK - A method for communicating in a wireless network includes receiving a signal intended to be spread over a first subcarrier and a second subcarrier. The method also includes determining the first subcarrier is subject to interference, and in this case decoding the received signal on the second subcarrier without demodulating the signal on the first subcarrier. The signal is intended to be spread in the frequency domain over multiple subcarriers or intended to be coded based on SFBC (space frequency block codes). The first and second subcarriers may be consecutive. Rate matching around the first stream or puncturing of the first stream enables proper decoding of the SFBC stream. Changing the spreading factor enables proper decoding in the case of frequency domain spreading over multiple streams. | 01-12-2012 |
20120034926 | COMPUTATION OF CHANNEL STATE FEEDBACK IN SYSTEMS USING COMMON REFERENCE SIGNAL INTERFERENCE CANCELATION - When enabled with common reference signal interference cancellation, a user equipment (UE) may still compute a channel state feedback value with consideration of any canceled interfering neighboring signals. When the neighboring cells are determined to be transmitting data during the time for which the channel state feedback value is being computed, the UE is able to derive the channel state feedback value considering those canceled interfering signals. The UE determines whether each neighboring cell is transmitting during the designated time either by obtaining signals that indicate the transmission schedule of the neighboring cells or by detecting the transmission schedule, such as based on the power class of the neighboring cells. If the UE determines that the neighboring cells are transmitting data during this time period, the UE will compute the channel state feedback value including consideration of the canceled interfering signals. | 02-09-2012 |
20120044928 | DETERMINATION OF NETWORK SYNCHRONIZATION - User equipment (UE) associated with synchronous networks operate in a synchronous mode while UEs associated with asynchronous networks operate in an asynchronous mode. When operating in a synchronous mode, a UE can significantly improve performance of synchronization signal detection, data decoding, and tracking loop management by using the interference cancellation (IC) techniques that are not available in an asynchronous mode of operation. Obtaining synchronization indicators and determining the synchronization status of the current network by UE is disclosed. The determination may be based on the synchronization indicator, whether detected through signal detection, signal measurements, signal analysis, or the like. | 02-23-2012 |
20120046056 | SAMPLE SELECTION FOR SECONDARY SYNCHRONIZATION SIGNAL (SSS) DETECTION - 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. | 02-23-2012 |
20120057480 | UE RECEIVER REFERENCE SIGNAL PROCESSING THAT UTILIZES RESOURCE PARTITIONING INFORMATION - 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). | 03-08-2012 |
20120087261 | DYNAMIC SWITCHING BETWEEN COMMON REFERENCE SIGNAL INTERFERENCE CANCELATION AND RESOURCE ELEMENT PUNCTURING IN A CO-CHANNEL HETEROGENEOUS NETWORK - Communication in a dominant interference scenario may be supported by performing inter-cell interference coordination (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, possibly except for a common reference signal (CRS). A UE can then communicate with the serving Node B on the protected resources in the presence of the interfering Node B and may observe no interference (possibly except for the CRS) from the interfering Node B. When CRS tones of an interferer may collide with control/data tones of a serving cell, CRS interference cancellation (CRS IC) or puncturing of interfered resource elements (REs) may be appropriate. Certain aspects of the present disclosure provide techniques, where the UE may dynamically switch between CRS IC and RE puncturing based on certain parameters. | 04-12-2012 |
20120190391 | PHYSICAL LAYER SIGNALING TO USER EQUIPMENT IN A WIRELESS COMMUNICATION SYSTEM - A method of wireless communication includes receiving physical layer signaling from a serving eNodeB in a wireless network. Interference estimation, interference cancellation and/or spatial equalization of user equipment is controlled in accordance with the received signaling. | 07-26-2012 |
20120201152 | INTERFERENCE ESTIMATION FOR WIRELESS COMMUNICATION - Interference on pilot signals and on data tones can be mismatched. Different types of interference estimates perform differently based on how the mismatch occurs. The resulting interference estimate may thus be inaccurate. Interference estimates based on pilot signals and also on data tones can both be evaluated for reliability. The more reliable of the two can then be selected. If the data tones estimate is selected, the estimate can be calculated from covariance matrices or from traffic-to-pilot ratios. | 08-09-2012 |
20120224499 | CHANNEL ESTIMATION FOR REFERENCE SIGNAL INTERFERENCE CANCELATION - Various aspects disclosed are directed to improvements to channel estimation through more efficient cancelation of neighboring common reference signals (CRS). Cancelation of CRS from other cells allows the user equipment (UE) a better opportunity for accurately detecting the reference signal of the current cell. Alternative aspects have a recursive element that uses previous estimates as the basis for the current channel estimate. The various aspects of the present disclosure generally have two alternative embodiments: (1) initializing the channel estimation for all cells with a previous channel estimate and cancellation of reference signals of non-target cells to accurately update channel estimate of the target cell; and (2) initializing the channel estimate for all cells with a previous channel estimate and cancelation of reference signals of all cells to accurately estimate residual channel estimate of the target cell and update its channel estimate. | 09-06-2012 |
20120243484 | ITERATIVE PILOT TONE CANCELLATION FOR IMPROVED CHANNEL ESTIMATION AND DECODING - Channel estimation is performed in a wireless network through cell/antenna pair ranking and iterative soft cancellation of pilot signals. Cell classification and ordering may be ranked and grouped for purposes of improving performance by dedicating hardware resources to higher priority received signals. A metric may be computed to rank the pairs. One such metric is reference signal (RS) power. Pairs may also be grouped into groups of pairs. Groups may be ordered by time-frequency resource and designated as serving-cell groups or non-serving cell groups. Higher priority pairs may be assigned a higher number of iterations. Higher priority groups may be processed first. Pairs which fall below a certain power threshold may be assigned no iterations. Iterations are distributed among hardware blocks to improve processing efficiency. Iteration numbers and hardware assignments may be modified to reach a desired complexity constraint. | 09-27-2012 |
20120327795 | INTERFERENCE ESTIMATION USING DATA TRAFFIC POWER AND REFERENCE SIGNAL POWER - 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. | 12-27-2012 |
20130044697 | NETWORK COORDINATION FOR IMPROVED INTERFERENCE CANCELLATION - 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. | 02-21-2013 |
20130107785 | TRACKING LOOP ENHANCEMENTS FOR MITIGATING SIGNAL INTERFERENCE AND ADJUSTING SIGNAL POWER | 05-02-2013 |
20130107805 | Reducing Complexity for Implementing Interference Cancellation Applied to Physical Channels of a Wireless Network | 05-02-2013 |
20130114437 | METHOD AND APPARATUS FOR INTERFERENCE CANCELLATION BY A USER EQUIPMENT USING BLIND DETECTION - In order to cancel any interference due to the second cell signal (e.g., from a non-serving cell) from a signal received at a UE, without receiving additional control information, the UE blindly estimates parameters associated with decoding the second cell signal. This may include determining a metric based on sets of symbols associated with the cell signals in order to determine parameters for the second cell signal, e.g., the transmission mode, modulation format, and/or spatial scheme of the second cell signal. The parameters for the signal may be determined based on a comparison of the metric with a threshold. When a spatial scheme and a modulation format is unknown, the blind estimation may include determining a plurality of constellations of possible transmitted modulated symbols associated with a potential spatial scheme and modulation format combination. Interference cancellation can be performed using the constellations and a corresponding probability weight. | 05-09-2013 |
20130114438 | REFERENCE SIGNAL DETECTION - 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. | 05-09-2013 |
20130114441 | CHANNEL STATE INFORMATION COMPUTATION FOR ENHANCED INTER-CELL INTERFERENCE COORDINATION - A delayed channel estimation is a channel state information (CSI) reference subframe having an index (N | 05-09-2013 |
20130114447 | INCREMENTAL INTERFERENCE CANCELATION CAPABILITY AND SIGNALING - Incremental interference cancelation (IC) capability management and signaling is disclosed. A mobile device selects certain groups of its individual IC capabilities to deactivate in response to various operating conditions it is experiencing. The mobile device reports its currently active IC capability to a serving base station, which uses information to determine whether to modify any existing communication conditions with respect to the reporting mobile device. The base station detects and analyzes the current communication conditions with respect to the reporting mobile device in light of the mobile device's currently active IC capabilities. The base station may modify such conditions through actions such as signaling the mobile device to activate or deactivate certain other groups of IC capabilities. The base station can make other modifications such as changing the communication schedule for the mobile device, modifying the control loop for channel quality indicator (CQI) reporting, and the like. | 05-09-2013 |
20130114449 | HANDLING MISMATCH OF CONTROL SPANS BETWEEN SERVING CELL AND INTERFERING CELLS FOR CONTROL AND DATA CHANNEL INTERFERENCE CANCELLATION - The following is directed to control and data channel interference cancellation between a serving cell and interfering cell. A first symbol of a subframe is processed to determine a control span of a serving cell and a control span of an interfering cell. The interference is then cancelled based on the determined control spans. | 05-09-2013 |
20130114455 | USER EQUIPMENT, BASE STATIONS, AND METHODS ALLOWING FOR HANDLING OF COLLIDING CHANNEL STATE INFORMATION REPORTS - Collision handling of channel state information (CSI) reports is described for enhanced inter-cell interference coordination (eICIC), coordinated multipoint transmission (CoMP), and/or carrier aggregation (CA). Various aspects include prioritization schemes to resolve collisions between different CSI reporting sets in relation to the same component carrier (CC) used with transmission. Multiple stages of prioritization may identify CSI for a report based on various criteria. Tie breaker criteria may be defined for priority among CSI reports that changes for different subframes. In other aspects, PUSCH is utilized to transmit CSI for prioritized reporting sets in a subframe. In yet other aspects, if parallel PUCCH is supported, colliding CSI may be handled on a per PUCCH basis. Other aspects may allow for prioritizing periodic CSI within each of multiple CCs, and then prioritizing over different CCs to handle an interaction of CSI reports for CA, eICIC and/or CoMP. | 05-09-2013 |
20130115987 | Hybrid Approach for Physical Downlink Shared Channel (PDSCH) Interference Cancellation - Certain aspects of the present disclosure relate to a hybrid approach for Physical Downlink Shared Channel (PDSCH) Interference Cancellation (IC). In certain aspects, if the PDSCH information is known for a serving cell but not be known for interfering cell(s), a hybrid approach that involves using Codeword-level IC (CWIC) for the serving cell and using Symbol-level IC (SLIC) for the interfering cells may be used for better IC performance. The hybrid IC approach may start with a UE attempting to decode the serving cell PDSCH. If the decode is unsuccessful, the UE may perform CWIC for the serving cell followed by SLIC using the results of the CWIC stage. After the SLIC stage, the UE may attempt to decode the serving cell PDSCH again. The UE may perform multiple operations of this method until the serving cell PDSCH is successfully decoded or a maximum number of iterations is reached. | 05-09-2013 |
20130128759 | METHOD AND APPARATUS FOR COMPUTING AND REPORTING CHANNEL QUALITY INDICATION (CQI) - Techniques for computing and reporting channel quality indication (CQI) are described. In an aspect, a plurality of CQI computation methods may be supported, and each CQI computation method may indicate how CQI should be computed. One CQI computation method may be selected for use. CQI may then be computed and reported in accordance with the selected CQI computation method. In an exemplary design, a user equipment (UE) may obtain a selected method for computing CQI, which may be chosen based on the UE capability and/or other factors. The selected method may specify (i) CQI computation for a specific codeword among a plurality of codewords or (ii) CQI computation by averaging signal quality across a plurality of layers used for transmission. The UE may compute CQI in accordance with the selected method, send the CQI to a base station, and receive data sent by the base station based on the CQI. | 05-23-2013 |
20130128792 | NETWORK-ASSISTED CELL ACCESS - Providing for access point assisted signal acquisition for heterogeneous access point wireless networks is described herein. By way of example, a closed subscriber group (CSG) base station, such as a home NodeB (HNB) can be configured to provide temporary, limited access to a UE that is not authorized to access the HNB. Upon receiving and rejecting an access probe, the HNB can negotiate with a surrounding macro network to provide service for the UE. Further, the HNB can forward signal acquisition data, to assist in proper decoding of pilot or synchronization signals of the macro network. In particular aspects, the HNB can reduce power or blank transmissions on reserved access resources to reduce interference for the UE. By these and other disclosed mechanisms, the HNB can assist a non-CSG subscriber to obtain network service, and mitigate interference effects due to proximity to the UE. | 05-23-2013 |
20130156013 | USER EQUIPMENT REFERENCE SIGNAL-BASED TIMING ESTIMATION - Estimation of timing errors is disclosed that uses user equipment reference signals (UERSs). A UE models each channel in a user equipment reference signal (UERS) as a channel on an adjacent UERS tone multiplied by a phase ramping term. This phase ramping term is determined using an estimator on the modeled channels. The UE then determines the equivalent timing error by mapping the phase ramping terms into the estimated timing errors in the time domain. In coordinated multipoint (CoMP) systems, the UERS-based timing error may be used to identify an aligned common reference signal (CRS) associated with the network entity transmitting the data. With this determination, the UE may estimate a CRS-based timing error and either substitute the CRS-based timing error for the UERS-based timing error or calculate a further average timing error based on both the CRS-based and UERS-based timing errors. | 06-20-2013 |
20130231123 | PER-CELL TIMING AND/OR FREQUENCY ACQUISITION AND THEIR USE ON CHANNEL ESTIMATION IN WIRELESS NETWORKS - 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. | 09-05-2013 |
20130250927 | Resource Partitioning Information for Enhanced Interference Coordination - 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. | 09-26-2013 |
20130273930 | COMPUTATION OF CHANNEL STATE FEEDBACK IN SYSTEMS USING COMMON INTERFERENCE SIGNAL INTERFERENCE CANCELATION - When enabled with common reference signal interference cancelation, a user equipment (UE) may still compute a channel state feedback value with consideration of any canceled interfering neighboring signals. When the neighboring cells are determined to be transmitting data during the time for which the channel state feedback value is being computed, the UE is able to derive the channel state feedback value considering those canceled interfering signals. The UE determines whether each neighboring cell is transmitting during the designated time either by obtaining signals that indicate the transmission schedule of the neighboring cells or by detecting the transmission schedule, such as based on the power class of the neighboring cells. If the UE determines that the neighboring cells are transmitting data during this time period, the UE will compute the channel state feedback value including consideration of the canceled interfering signals. | 10-17-2013 |
20130294333 | SYSTEMS AND METHODS FOR REDUCED OVERHEAD IN WIRELESS COMMUNICATION SYSTEMS - Systems and methods are disclosed which implement one or more overhead reduction technique, if channel conditions favorable to implementation of overhead reduction are present. The one or more overhead reduction technique may have one or more restriction corresponding to the channel for which the overhead reduction technique is implemented. The one or more overhead reduction technique implemented may include time-domain bundling, frequency-domain bundling, and pattern adaptation. Pattern adaptation may include pattern code-domain reduction, pattern timing-domain reduction, and pattern frequency-domain reduction. | 11-07-2013 |
20130308466 | TIME AND FREQUENCY ACQUISITION AND TRACKING FOR OFDMA WIRELESS SYSTEMS - Obtaining a timing reference in wireless communication is facilitated when desiring to communicate with a weak serving base station (such as an evolved NodeB) in the presence of a stronger interfering base station. The user equipment (UE) may track a stronger interfering base station's timing, or the UE may track a timing that is derived by a composite power delay profile (PDP) from multiple base stations. The composite PDP may be constructed by adjusting individual base station PDPs according to a weighting scheme. The timing obtained in such a manner may be used for estimation of the channel of the interfering base station and cancelling interfering signals from the base station. It may also be used to estimate the channel of the serving base station after adding a backoff. The UE may track a stronger interfering base station's frequency, or the UE may track a composite frequency. | 11-21-2013 |
20130336193 | NETWORK INFORMATION FOR ASSISTING USER EQUIPMENT - A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus may be a UE that acquires information regarding an interfering non-serving cell and uses the information to improve decoding of serving cell signals. The method includes receiving, from a serving evolved Node B (eNB), information that includes one or more transmission characteristics of at least one non-serving cell and performing at least one of interference cancellation, demodulation, or provides an improved channel quality indicator (CQI) based on the received information. | 12-19-2013 |
20130336249 | APPARATUS AND METHODS FOR RESOURCE ELEMENT GROUP BASED TRAFFIC TO PILOT RATIO AIDED SIGNAL PROCESSING - A method, a computer program product, and an apparatus are provided. The methods and apparatus for wireless communication include receiving a transmission, the transmission including a plurality of resource element groups (REGs). Aspects of the methods and apparatus include selecting a set of REGs from the plurality of REGs, the set of REGs including at least one REG and determining a traffic to pilot ratio (TPR) for the set of REGs based on the transmission and reference signals in the transmission. Aspects of the methods and apparatus include determining whether the set of REGs includes at least one of control information or data based on the TPR and canceling at least one of control information or data from the set of REGs based on the TPR. | 12-19-2013 |
20140003267 | CHANNEL STATE INFORMATION REPORTING FOR PARTIALLY CANCELLED INTERFERENCE | 01-02-2014 |
20140023001 | APPARATUSES AND METHODS OF DETECTION OF INTERFERING CELL COMMUNICATION PROTOCOL USAGE - A method, an apparatus, and a computer program product for wireless communication are provided in connection with UE centric interfering cell communication protocol usage detection. In one example, a communications device (e.g., a UE) is equipped to receive one or more signals from each cell of a plurality of cells including a set of interfering cells. The set of interfering cells includes one or more interfering cells. The UE can detect system release version information for at least one cell from the set of interfering cells, and then modify its communication processing with a serving cell based on the detected system release version information. | 01-23-2014 |
20140029456 | INTERFERENCE ESTIMATION IN THE PRESENCE OF ePDCCH TRANSMISSIONS - A method of wireless communication is presented. The method includes determining, for each resource element group of a resource block pair, whether an interfering control channel is present on the resource block pair. The determination may be based on whether estimated power of the resource element groups varies among two or more resource element groups. The method also includes estimating the interference on the resource block pair based on the determination. | 01-30-2014 |
20140036838 | METHOD AND APPARATUS THAT FACILITATES DETECTING SYSTEM INFORMATION BLOCKS IN A HETEROGENEOUS NETWORK - Aspects are disclosed for detecting a system information block (SIB) within a heterogeneous network. In one aspect, a type of scheduling information pertaining to an SIB is selected, and a parameter known to a wireless terminal is associated with the type of scheduling information. The wireless terminal then decodes the SIB by deriving the scheduling information from the known parameters, without having to decode a Physical Downlink Control Channel. | 02-06-2014 |
20140098773 | METHOD AND APPARATUS FOR INTERFERENCE CANCELLATION BY A USER EQUIPMENT USING BLIND DETECTION - In order to cancel any interference due to the second signal (e.g., from a non-serving cell) from a signal received at a UE, without receiving additional control information, the UE blindly estimates parameters associated with decoding the second signal. This may include determining a metric based on sets of symbols associated with the signals in order to determine parameters for the second signal, e.g., the transmission mode, modulation format, and/or spatial scheme of the second signal. The parameters for the signal may be determined based on a comparison of the metric with a threshold. When a spatial scheme and a modulation format is unknown, the blind estimation may include determining a plurality of constellations of possible transmitted modulated symbols associated with a potential spatial scheme and modulation format combination. Interference cancellation can be performed using the constellations and a corresponding probability weight. | 04-10-2014 |
20140135025 | TIME AND FREQUENCY ACQUISITION AND TRACKING FOR OFDMA WIRELESS SYSTEMS - Obtaining a timing reference in wireless communication is facilitated when desiring to communicate with a weak serving base station (such as an evolved NodeB) in the presence of a stronger interfering base station. The user equipment (UE) may track a stronger interfering base station's timing, or the UE may track a timing that is derived by a composite power delay profile (PDP) from multiple base stations. The composite PDP may be constructed by adjusting individual base station PDPs according to a weighting scheme. The timing obtained in such a manner may be used for estimation of the channel of the interfering base station and cancelling interfering signals from the base station. It may also be used to estimate the channel of the serving base station after adding a backoff. The UE may track a stronger interfering base station's frequency, or the UE may track a composite frequency. | 05-15-2014 |
20140161043 | SAMPLE SELECTION FOR SECONDARY SYNCHRONIZATION SIGNAL (SSS) DETECTION - 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. | 06-12-2014 |
20140161044 | SAMPLE SELECTION FOR SECONDARY SYNCHRONIZATION SIGNAL (SSS) DETECTION - 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. | 06-12-2014 |
20140204857 | MANAGING INTERFERENCE IN A NETWORK - A method, an apparatus, and a computer program product for wireless communication are provided. In one configuration, the apparatus may be a UE. The UE determines an MCS that would facilitate interference suppression of an interfering first cell transmission from a first cell when decoding a second cell transmission from a second cell at the UE. The interfering first cell transmission is a transmission unintended for the UE. The second cell transmission is a transmission intended for the UE. The UE transmits information indicating the determined MCS for the first cell. The UE receives a transmission including the second cell transmission from the second cell and the interfering first cell transmission from the first cell. The UE demodulates and/or decodes the second cell transmission from the received transmission based on the determined MCS. | 07-24-2014 |
20140211655 | RADIO LINK MONITORING (RLM) AND REFERENCE SIGNAL RECEIVED POWER (RSRP) MEASUREMENT FOR HETEROGENEOUS NETWORKS - A method for communicating in an advanced long term evolution (LTE-A) network using common reference signal (CRS) resources associated with different interference levels due to resource partitioning is disclosed. Signals are received from an eNodeB indicating a subset of CRS resources for radio link monitoring (RLM) and/or reference signal received power (RSRP) measuring. The subset of CRS resources includes the CRS resources expected to have lower interference from the interfering eNodeBs. RLM and/or RSRP measurements are performed based on the indicated subset. | 07-31-2014 |
20140269246 | INTERFERENCE CANCELLATION - A method to enhance coverage and/or throughput in a heterogeneous wireless network includes detecting interference between a neighboring cell and a serving cell. The method also includes cancelling the interference using an adaptive technique based on whether the interference has colliding Common Reference Signal (CRS) tones or whether the interference has colliding Dedicated Reference Signal (DRS) tones. | 09-18-2014 |
20140293971 | EMPLOYING NEIGHBORING CELL ASSISTANCE INFORMATION FOR INTERFERENCE MITIGATION - Certain aspects of the present disclosure relate to methods and apparatus for employing a neighboring cell's assistance information for interference mitigation (e.g., by conveying the information to a user equipment). A base station (BS) may determine assistance information for a neighboring cell and convey it to a user equipment (UE). A UE may receive assistance information for a neighboring cell and use that information for performing interference cancellation or suppression on received signals. The UE may receive the assistance information from a serving cell or a non-serving cell. The assistance information may be valid for a particular transmission instance, for a known period of time, or until updated by a BS. | 10-02-2014 |
20140301251 | INTERFERENCE CANCELLATION/SUPPRESSION IN TDD WIRELESS COMMUNICATIONS SYSTEMS - A wireless user equipment (UE) may receive a downlink transmission from a base station in a first subframe of a first subframe configuration, and determine that a neighboring base station is operating according to a second subframe configuration. The UE may modify interference operations for the downlink transmission in the first subframe based on the determination to account for the neighboring base station operating according to the different subframe configuration. Modifying interference operations may include, for example, skipping interference operations, applying different interference operations to a subframe or a portion of a subframe, or a combination thereof. Modifying interference operations may be based on one or more characteristics of the neighboring base station communications. | 10-09-2014 |
20140301268 | NETWORK ASSISTED INTERFERENCE CANCELLATION/SUPPRESSION FOR MULTIPLE SERVICES - Certain aspects of the present disclosure relate to methods and apparatus for network assisted interference cancellation (IC) and interference suppression (IS) for multiple services. According to aspects a user equipment (UE) may determine information regarding system parameters for one or more types of communications services used to transmit potentially interfering signals in one or more neighbor cells, wherein a type of the information determined depends on the type of communications service. The UE may perform interference management using the determined information to cancel or suppress interference caused by the potentially interfering signals. | 10-09-2014 |
20140301271 | CHANNEL STATE INFORMATION REFERENCE SIGNAL (CSI-RS) HANDLING FOR NETWORK ASSISTED INTERFERENCE CANCELLATION - A method of wireless communication includes transmitting channel state information reference signal (CSI-RS) configuration information to a user equipment (UE). The CSI-RS configuration information is transmitted so that the UE may mitigate interference caused by interfering CSI-RSs. The CSI-RS configuration may be a CSI-RS configuration of a neighbor cell. | 10-09-2014 |
20140301272 | COMMON REFERENCE SIGNAL INTERFERENCE CANCELLATION TRIGGERING IN HOMOGENEOUS NETWORKS - A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus determines whether one or more criteria for triggering interference cancellation in a homogeneous network are satisfied. The apparatus transmits a signal to a UE to control triggering the interference cancellation at the UE if the one or more criteria are satisfied. | 10-09-2014 |
20140301292 | TPR MANAGEMENT FOR EPDCCH IN LTE - For an enhanced physical downlink control channel (EPDCCH), unlimited traffic-to-pilot ratio (TPR) variations across resource elements of a physical resource block (PRB) pair is problematic because of the detrimental affect the variations will have on the ability of a user equipment (UE) to perform inter-cell/intra-cell interference suppression (IS) and/or interference cancellation (IC) on EPDCCH of an interfering cell. A TPR limitation is placed on EPDCCH to facilitate IS/IC without causing practical limitations on EPDCCH management by an eNB. Accordingly, a method, an apparatus, and a computer program product for wireless communication are provided. The apparatus identifies a plurality of resource elements of at least one PRB pair for transmitting one or more control channels, divides the plurality of identified resource elements into one or more groups, and restricts a plurality of resource elements in a respective group to a TPR. | 10-09-2014 |
20140301298 | METHODS AND APPARATUS FOR TRANSMISSION RESTRICTION AND EFFICIENT SIGNALING - Certain aspects of the present disclosure relate to methods and apparatus for transmission restriction and efficient signaling. A base station (BS) may determine information regarding a restricted set of system parameters used for transmission from at least one of the serving BS or one or more potentially interfering BSs and signal the information to a user equipment (UE). According to certain aspects, a UE may receive the signaling of information regarding the restricted set of system parameters used for transmission from at least one of the serving BS or the one or more potentially interfering BSs and use the information to cancel interference by transmissions from the one or more potentially interfering BSs or serving BS. | 10-09-2014 |
20140301309 | LOW COMPLEXITY BLIND DETECTION OF TRANSMISSION PARAMETERS OF INTERFERERS - A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus reduces inference in a received signal. The apparatus receives a signal including transmissions from a plurality of cells. The apparatus determines transmission parameter hypotheses associated with the plurality of cells. Each transmission parameter hypothesis from the transmission parameter hypotheses includes a set of transmission parameters associated with all the cells from the plurality cells. The apparatus selects at least one transmission parameter hypothesis based on a first metric applied to each hypothesis. The apparatus refines transmission parameters associated with at least one cell from the plurality of cells. The refining includes improving an accuracy of the transmission parameters associated with the at least one cell based on a second metric associated with each cell individually. | 10-09-2014 |
20140302863 | VIRTUAL CELL MANAGEMENT FOR INTERFERENCE SUPPRESSION AND INTERFERENCE CANCELLATION IN LTE - In some aspects, a method for performing wireless communication includes configuring a set of virtual cells for user equipments (UEs). One or more virtual cells of the set is associated with at least one set of parameters. The method also includes transmitting information, to the UEs, regarding the set of the virtual cells, and operating, for a same virtual cell, according to a same set of parameters for some or all of the UEs. In other aspects, a method for performing wireless communications includes receiving, from a node, information regarding, for a UE, a set of virtual cells associated with a set of parameters. The method also includes communicating with the node. The communication is based on a virtual cell and its associated set of parameters. | 10-09-2014 |
20140307703 | PRECODER RESOURCE BUNDLING INFORMATION FOR INTERFERENCE CANCELLATION IN LTE - Methods, systems, and devices are described for interference cancellation/interference suppression (IC/IS) of neighbor cell transmissions. A UE may receive a downlink transmission from a base station and also receive interfering signals from one or more neighboring base stations. The UE may be configured to perform IC/IS operations on the interfering signals. In order to enhance IC/IS operations, the UE may evaluate whether resource bundling is used for the interfering signals. The UE may modify IC/IS operations for one or more subframes responsive to the evaluation. Modifying IC/IS operations may include, for example, using information related to the bundling at the neighboring base station(s) to cancel the interfering signals from the base station(s). | 10-16-2014 |
20140334434 | REFERENCE SIGNAL DETECTION - 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. | 11-13-2014 |
20140341050 | CHANNEL ESTIMATE UNDER NON-UNIFORM REFERENCE SIGNAL PATTERN - Reference signals may not uniformly span over time and/or frequency on a resource unit. For example, reference signals may non-uniformly occupy symbols of a subframe. Alternatively, reference signals normally transmitted over certain tones of a subframe may have to be punctured to avoid collisions with a PSS and/or SSS transmitted over the same tones. Consequently, a UE may only be able to use a subset of reference signal tones for performing channel estimation. Accordingly, a method, an apparatus, and a computer program product for wireless communication are provided for improving channel estimation under a non-uniform signal pattern. The apparatus indicates to a UE to utilize a subset of reference signals to derive a channel estimate for demodulating data in a specific subframe, and transmits a plurality of subframes, the plurality of subframes including the reference signals and the specific subframe, the specific subframe including a PSS and/or SSS. | 11-20-2014 |
20140348019 | CQI Estimation in a Wireless Communication Network - Techniques for estimating and reporting channel quality indicator (CQI) are disclosed. Neighboring base stations may cause strong interference to one another and may be allocated different resources, e.g., different subframes. A UE may observe different levels of interference on different resources. In an aspect, the UE may determine a CQI for resources allocated to a base station and having reduced or no interference from at least one interfering base station. In another aspect, the UE may determine multiple CQI for resources of different types and associated with different interference levels. For example, the UE may determine a first CQI based on at least one first subframe allocated to the base station and having reduced or no interference from the interfering base station(s). The UE may determine a second CQI based on at least one second subframe allocated to the interfering base station(s). | 11-27-2014 |