Patent application number | Description | Published |
20090197603 | SERVING BASE STATION SELECTION IN A WIRELESS COMMUNICATION NETWORK - Techniques for selecting a serving base station for a terminal in a wireless communication network are described. In one design, multiple candidate base stations for the terminal may be identified, with each candidate base station being a candidate for selection as the serving base station for the terminal. The multiple candidate base stations may include base stations with different transmit power levels and/or may support interference mitigation. One of the multiple candidate base stations may be selected as the serving base station. In one design, the serving base station may be selected based on at least one metric for each candidate base station. The at least one metrics may be for pathloss, effective transmit power, effective geometry, projected data rate, control channel reliability, network utility, etc. The selected candidate base station may have a lower SINR than a highest SINR among the multiple candidate base stations. | 08-06-2009 |
20090201826 | SEGMENT SENSITIVE SCHEDULING - Systems and methods of scheduling sub-carriers in an OFDMA system in which a scheduler takes into account channel conditions experienced by the communication devices to optimize channel conditions. The scheduler can partition a set of sub-carriers spanning an operating bandwidth into a plurality of segments. The segments can include a plurality of global segments that each includes a distinct non-contiguous subset of the sub-carriers spanning substantially the entire operating bandwidth. One or more of the global segments can be further partitioned into a plurality of local segments that each has a bandwidth that is less than a channel coherence bandwidth. The scheduler determines channel characteristics experienced by each communication device via reporting or channel estimation, and allocates one or more segments to communication links for each device according to the channel characteristics. | 08-13-2009 |
20090201846 | SYSTEM AND METHOD FOR SCHEDULING OVER MULTIPLE HOPS - Systems and methodologies are described that facilitate scheduling over multiple hops in a wireless communication network. Radio resources can be partitioned into sets of sub-frames that can be allocated statically and/or dynamically. Statically allocated radio resources can be reassigned over time based on the loading on each hop and/or throughput imbalance. In addition, dynamic assignment of sub-frames to each hop can be based on traffic or channel conditions. Moreover, the radio resources can be dynamically allocated in a distributed scheme, wherein a base station controls the scheduling of resources, or a centralized scheme, wherein a relay station controls the scheduling of resources. Furthermore the allocation of radio resources can be transparent or explicit. In the transparent case, the access terminal listens directly to the base station, and the relay station does not transmit control information, such as DL or UL assignments. Conversely, when the allocation of resources is explicit the relay station does transmit control information. | 08-13-2009 |
20090201872 | SEGMENT SENSITIVE SCHEDULING - Systems and methods of scheduling sub-carriers in an OFDMA system in which a scheduler takes into account channel conditions experienced by the communication devices to optimize channel conditions. The scheduler can partition a set of sub-carriers spanning an operating bandwidth into a plurality of segments. The segments can include a plurality of global segments that each includes a distinct non-contiguous subset of the sub-carriers spanning substantially the entire operating bandwidth. One or more of the global segments can be further partitioned into a plurality of local segments that each has a bandwidth that is less than a channel coherence bandwidth. The scheduler determines channel characteristics experienced by each communication device via reporting or channel estimation, and allocates one or more segments to communication links for each device according to the channel characteristics. | 08-13-2009 |
20090245331 | SIGNALING MESSAGE TRANSMISSION IN A WIRELESS COMMUNICATION NETWORK - Techniques for sending signaling messages in a wireless communication network are described. In an aspect, a signaling message (e.g., a reduce interference request) may be sent by mapping it to at least one specific subcarrier among a set of subcarriers reserved for sending the signaling message. The at least one subcarrier may be selected based on the message value. A signal may be sent on the at least one subcarrier in multiple symbol periods to convey the signaling message. In another aspect, a reduce interference request may be sent based on an orthogonal resource among orthogonal resources available for sending reduce interference requests. In one design, an orthogonal sequence may be selected based on the request and may be spread across a resource segment. In another design, the reduce interference request may be processed to obtain modulation symbols, and each modulation symbol may be spread across multiple subcarriers in one symbol period. | 10-01-2009 |
20090286482 | SPATIAL INTERFERENCE MITIGATION SCHEMES FOR WIRELESS COMMUNICATION - Techniques for transmitting and receiving data with spatial interference mitigation in a wireless communication network are described. In one design, a cell may receive preceding information from a first user equipment (UE) communicating with the cell and spatial feedback information (SFI) from a second UE not communicating with the cell. The cell may select a preceding matrix based on the preceding information and the SFI. The preceding matrix may steer a transmission toward the first UE and away from the second UE. The cell may send a reference signal based on the preceding matrix, send a resource quality information (RQI) request to the first UE, receive RQI determined by the first UE based on the reference signal, and determine a modulation and coding scheme (MCS) based on the RQI. The cell may then send a data transmission to the first UE with the preceding matrix and in accordance with the MCS. | 11-19-2009 |
20090286562 | SPATIAL INTERFERENCE MITIGATION FOR WIRELESS COMMUNICATION - Techniques for transmitting and receiving data with spatial interference mitigation in a wireless network are described. In one design of transmitting data with spatial interference mitigation, a first station (e.g., a cell) may receive spatial feedback information (SFI) from a second station (e.g., an interfered UE) that is not communicating with the first station. The second station may also receive preceding information from a third station (e.g., a served UE). The first station may send a data transmission to the third station based on the preceding information and the SFI in order to reduce interference to the second station. In one design, the SFI may include spatial nulling information. The first station may send the data transmission based on the spatial nulling information to steer the data transmission in a direction away from the second station. | 11-19-2009 |
20090323577 | BROADCAST-MULTICAST TRANSMISSION WITH RATE ADAPTION - Techniques for supporting broadcast/multiple transmission to multiple terminals with feedback and rate adaptation are described. In an aspect, a combination of HARQ and at least one shared feedback channel may be used to support broadcast/multicast transmission. In one design, a base station may send at least one transmission of a packet to multiple terminals, one transmission at a time. The base station may receive feedback information (e.g., NAK) for the packet from the terminals on the shared feedback channel(s). The base station may determine whether to terminate the packet early and/or may select at least one transmission parameter for another packet based on the feedback information for the packet. In another aspect, a transport format for a broadcast/multicast transmission may be selected based on CQI information from terminals receiving the transmission. The terminals may send CQI information at a slow rate and/or only certain terminals may send CQI information. | 12-31-2009 |
20090325626 | MULTI-CARRIER OPERATION IN A WIRELESS COMMUNICATION NETWORK - Techniques for communicating on multiple carriers in a wireless communication network are described. In an aspect, different transmit power levels may be used for different carriers to mitigate interference. A first base station may be assigned one or more carriers among multiple carriers available for communication. A second base station may be assigned one or more carriers not assigned to the first base station. Each base station may communicate on each assigned carrier at a first (e.g., full) transmit power level and may communicate on each unassigned carrier at a second (e.g., lower) transmit power level lower. The first and second base stations may belong in different power classes or support different association types. In another aspect, control information may be sent on a designated carrier to support communication on multiple carriers. In yet another aspect, a base station may broadcast bar information indicating the status of carriers. | 12-31-2009 |
20100008244 | DOMINANT INTERFERER INDICATION IN ACCESS PROBE - Systems and methodologies are described that facilitate indicating a dominant interferer to a target serving base station in a wireless communication environment. A mobile device can detect presence or absence of a dominant interferer. Further, an access probe that includes information related to the presence or absence of the dominant interferer can be generated. For example, the information can be included in a payload of the access probe as an explicit flag, an explicit indication of an interference level, a Channel Quality Indicator (CQI) value (e.g., reserved versus non-reserved, . . . ), etc. Moreover, the access probe can be transmitted to the target serving base station to initiate an access procedure. The target serving base station can select a time-frequency resource to be utilized for a responsive downlink transmission (e.g. access grant signal, subsequent access related message, . . . ) as a function of the information included in the access probe. | 01-14-2010 |
20100008294 | METHOD AND APPARATUS FOR USING UPLINK CONTROL INFORMATION FOR INTER-CELL DECODING AND INTERFERENCE CANCELLATION - Techniques for supporting data transmission on the uplink in a wireless network are described. In an aspect, a user equipment (UE) may send a data transmission to a serving base station and may send uplink control information (UCI) to a non-serving base station. The UCI may include pertinent information to allow the non-serving base station to process the data transmission from the UE. In one design, the UCI may allow the non-serving base station to estimate the interference due to the data transmission from the UE and to cancel the interference at the non-serving base station. The interference cancellation may improve the received signal quality at the non-serving base station. After the interference cancellation, the non-serving base station may process a data transmission from another UE served by the base station. | 01-14-2010 |
20100020771 | METHOD AND APPARATUS FOR MITIGATING PILOT POLLUTION IN A WIRELESS NETWORK - Techniques for mitigating pilot pollution in a wireless network are described. In an aspect, pilot pollution may be mitigated by reducing density and/or transmit power of common pilots whenever possible. A cell may send a common pilot at a first density and a first transmit power level during a first time period and may send the common pilot at a second density and a second transmit power level during a second time period. The second density may be lower than the first density and/or the second transmit power level may be lower than the first transmit power level. Lower density may be achieved by sending the common pilot less frequently, on fewer subcarriers, and/or from fewer antennas. The cell may determine whether to reduce the density and/or transmit power of the common pilot based on network loading, SINRs of terminals, etc. In another aspect, pilot pollution may be mitigated by performing pilot cancellation at a terminal. | 01-28-2010 |
20100027451 | REVERSE LINK POWER CONTROL FOR AN OFDMA SYSTEM - Techniques for performing power control of multiple channels sent using multiple radio technologies are described. The transmit power of a reference channel, sent using a first radio technology (e.g., CDMA), is adjusted to achieve a target level of performance (e.g., a target erasure rate) for the reference channel. The transmit power of a data channel, sent using a second radio technology (e.g., OFDMA), is adjusted based on the transmit power of the reference channel. In one power control scheme, a reference power spectral density (PSD) level is determined based on the transmit power of the reference channel. A transmit PSD delta for the data channel is adjusted based on interference estimates. A transmit PSD of the data channel is determined based on the reference PSD level and the transmit PSD delta. The transmit power of the data channel is then set to achieve the transmit PSD for the data channel. | 02-04-2010 |
20100034315 | REVERSE LINK POWER CONTROL FOR AN OFDMA SYSTEM - Techniques for performing power control of multiple channels sent using multiple radio technologies are described. The transmit power of a reference channel, sent using a first radio technology (e.g., CDMA), is adjusted to achieve a target level of performance (e.g., a target erasure rate) for the reference channel. The transmit power of a data channel, sent using a second radio technology (e.g., OFDMA), is adjusted based on the transmit power of the reference channel. In one power control scheme, a reference power spectral density (PSD) level is determined based on the transmit power of the reference channel. A transmit PSD delta for the data channel is adjusted based on interference estimates. A transmit PSD of the data channel is determined based on the reference PSD level and the transmit PSD delta. The transmit power of the data channel is then set to achieve the transmit PSD for the data channel. | 02-11-2010 |
20100039948 | INTERFERENCE MANAGEMENT BASED ON ENHANCED PILOT MEASUREMENT REPORTS - Techniques for managing interference in a wireless network are described. A base station may receive enhanced pilot measurement reports from user equipments (UEs) and may make an interference management decision based on the received reports. The base station may select a serving base station for a UE based on an enhanced pilot measurement report received from the UE. The base station may determine resources with a low target interference level at a neighbor base station and may avoid scheduling a UE for uplink transmission on the resources. The base station may also determine whether to reserve resources for a neighbor base station based on data performance of the neighbor base station, whether the neighbor base station observes high interference from UEs served by the base station, or whether UEs served by the neighbor base station observe high interference from the base station, which may be determined based on the enhanced pilot measurement reports. | 02-18-2010 |
20100056215 | DISTRIBUTED DOWNLINK COORDINATED MULTI-POINT (CoMP) FRAMEWORK - Systems and methodologies are described that facilitate dynamically forming clusters in a wireless communication environment. A set of non-overlapping clusters can be formed dynamically over time and in a distributed manner. Each of the clusters can include a set of base stations and a set of mobile devices. The clusters can be yielded based upon a set of local strategies selected by base stations across the network converged upon through message passing. For example, each base station can select a particular local strategy as a function of time based upon network-wide utility estimates respectively conditioned upon implementation of the particular local strategy and disparate possible local strategies that can cover the corresponding base station. Moreover, operation within each of the clusters can be coordinated. | 03-04-2010 |
20100061317 | METHOD AND SYSTEM TO INDICATE A DESIRED TRANSMIT POWER AND SOFT POWER CONTROL IN A WIRELESS NETWORK - In a wireless communication system, short-term interference mitigation may be used to mitigate (e.g., to avoid or reduce) interference on a given link in order to improve performance of data transmission. The interference mitigation reduces transmit power of interfering transmissions so that a higher signal-to-noise-and-interference ratio (SINR) can be achieved for a desired data transmission. A node may observe high interference from an interfering node that degrades performance of data transmission sent on that link. By taking advantage of an communication path with the interfering node (e.g., wireless data/control channel, backhaul network connection, or analog broadcast signal), the transmitting node can successfully complete time critical communications while allowing the interfering node to also simultaneously communicate without reducing overall resources nor burdening any managing nodes. | 03-11-2010 |
20100067421 | APPARATUS AND METHODS FOR CONTROLLING AN IDLE MODE IN A WIRELESS DEVICE - Apparatus and methods are disclosed for control of an idle mode in a wireless device. In particular, the idle mode duty cycle of a preamble transmission by an access point (AP), as an example, is variably or adaptively set in response to determined conditions of the wireless neighborhood. The conditions determined include the whether or not other wireless devices are present in the vicinity of sensing wireless device, as well as the state of those devices present, such as whether they are in an idle mode or an active mode. | 03-18-2010 |
20100067422 | APPARATUS AND METHODS FOR CONTROLLING A SLEEP MODE IN A WIRELESS DEVICE - Apparatus and methods for controlling sleep mode in a wireless device are disclosed. The sleep mode is controlled using low power detection of RF beacon signals of known frequencies to reduce power consumption of the wireless device during sleep modes. Detection is achieved by using passive or low power elements in a receive chain that filters received signals allowing beacon signals of particular frequencies to pass, which are accumulated with passive or low power circuit elements requiring no external power source. The accumulated energy is compared to a threshold to determine the presence of the beacon with sleep circuitry. When the beacon is detected, the full RF receiver is triggered to wake up. Use of low power elements and passive elements, affords a beneficial increase in power savings for the wireless device, which is particularly helpful in wireless access points or relay stations that have an alternative power sourcing such as battery or solar power. | 03-18-2010 |
20100085917 | METHOD AND APPARATUS FOR COOPERATION STRATEGY SELECTION IN A WIRELESS COMMUNICATION SYSTEM - Systems and methodologies are described that facilitate cooperation strategy selection for a network multiple-in-multiple-out (N-MIMO) communication system. As described herein, one or more nodes in a communication system capable of N-MIMO communication can calculate marginal utilities, projected per-user rates, and/or other parameters corresponding to respective associated users. Based on these calculations, respective network nodes can perform user scheduling and selection, cell scheduling and selection, selection of a cooperation strategy (e.g., coordinated silencing, joint transmission, coordinated beamforming, etc.), and/or other operations to provide cooperative communication for respective users. As further described herein, projected rate calculation for a given user can be adjusted based on processing or channel implementation loss associated with the user, interference nulling capability of the user, or other factors. As additionally described herein, these and/or other parameters can be fed back by respective users to a serving network node and/or mandated via system performance requirements. | 04-08-2010 |
20100091892 | METHOD AND APPARATUS FOR CHANNEL FEEDBACK BY MULTIPLE DESCRIPTION CODING IN A WIRELESS COMMUNICATION SYSTEM - A communication system comprises evolved base nodes (eNBs) communicating via an over-the-air (OTA) link with low mobility user equipment (UE). A network can utilize the eNBs for cooperative beam shaping for interference nulling based upon a number of factors UE (e.g., coordinated multi-point (COMP) optimization for feedback, quality of service (QoS), fairness, etc.). The UE advantageously transmits multiple description coding (MDC) that supports a determination by the eNBs that coherent channel conditions (e.g., frequency and/or time invariance) exists for combining feedback reports to realize reduced quantization error. In addition, the MDC feedback reports still support incoherent channel states in which each report can be used individually for interference nulling/beamforming. MDC can be performed with one codebook or a plurality of codebooks. | 04-15-2010 |
20100091893 | METHOD AND APPARATUS FOR CHANNEL FEEDBACK IN A WIRELESS COMMUNICATION SYSTEM - A communication system comprises evolved base nodes (eNBs) communicating via an over-the-air (OTA) link with low mobility user equipment (UE). A network can utilize the eNBs for cooperative beam shaping for interference nulling based upon a number of factors UE (e.g., coordinated multi-point (COMP) optimization for feedback, quality of service (QoS), fairness, etc.). The UE advantageously transmits adaptive rate and payload channel state feedback, trading accuracy versus delay based upon mobility of the UE. Channel coherence across a transmission interval (frequency and/or time invariance) provides an opportunity with sufficiently low mobility for transmitting a larger accuracy feedback report over one or more feedback reports for decoding at the eNB. Reduced quantization error can be realized via multi-level coding, one codebook multiple description coding (MDC), and use of N-best code representations from one codebook with MDC. | 04-15-2010 |
20100097976 | INCREMENTAL REDUNDANCY RELAYS FOR WIRELESS COMMUNICATION - Techniques for relaying transmissions in a wireless communication network are described. In one design, a relay may receive at least one assignment for a packet, which may be sent to the relay or intercepted by the relay. The relay may receive at least one transmission of a packet sent from a transmitter to a receiver. The relay may process the at least one transmission to decode the packet and may generate at least one additional transmission of the packet after correctly decoding the packet. The relay may send the at least one additional transmission of the packet to the receiver. The transmission(s) and the additional transmission(s) may be HARQ transmissions with different redundancy information for the packet. The transmitter may send transmissions until an acknowledgement (ACK) is received from the receiver or the relay. The relay may send additional transmissions until an ACK is received from the receiver. | 04-22-2010 |
20100099428 | NULL PILOTS FOR INTERFERENCE ESTIMATION IN A WIRELESS COMMUNICATION NETWORK - Techniques for transmitting null pilots to support interference estimation in a wireless network are described. A null pilot is non-transmission on designated time-frequency resources by a cell or a cluster of cells supporting cooperative transmission to a UE. The received power of the null pilot from the cell or cluster of cells may be indicative of interference from other cells. In one design, a cell in the cluster may determine resources for sending a null pilot by the cell. The cell may transmit the null pilot (i.e., send no transmissions) on the resources to allow UEs to estimate out-of-cluster interference. Some or all cells in the cluster may transmit null pilots on the same resources. The cell may receive interference and channel information from the UE and may send data transmission to the UE based on the interference and/or channel information. Remaining cells in the cluster may reduce interference to the UE. | 04-22-2010 |
20100099449 | INTERFERENCE MANAGEMENT WITH REDUCE INTERFERENCE REQUESTS AND INTERFERENCE INDICATORS - Techniques for managing interference in a wireless network are described. In an aspect, reduce interference requests and interference indicators may be used for interference management to enable operation in scenarios with dominant interferers. In one design, a terminal may receive a reduce interference request from a first base station requesting lower interference on specified time-frequency resources. The terminal may also receive an interference indicator conveying the interference observed by a second base station. The terminal may determine its transmit power based on the reduce interference request and the interference indicator. For example, the terminal may determine an initial transmit power based on the reduce interference request (or the interference indicator) and may adjust the initial transmit power based on the interference indicator (or the reduce interference request) to obtain its transmit power. The terminal may transmit data to a serving base station at the determined transmit power. | 04-22-2010 |
20100103821 | METHOD AND APPARATUS FOR ANCHOR CELL DESIGNATION IN NETWORK MIMO - Systems and methods that designate a control attachment point(s) during transmission of data in a Coordinated Multipoint (CoMP) system. The control attachment point is represented by an anchor cell to address control signaling and represent a User Equipment's (UE) interaction with the wireless communication system from a perspective of control (e.g., supplying/sending grants to the UE, transmitting/receiving ACKS on the downlink/uplink to the UE, control information (CQI), and the like.) The cells can further engage in backhaul transfer of information therebetween, and dynamic switching/change of anchor point based on criteria such as control loading, channel quality, and the like can further be implemented. | 04-29-2010 |
20100103834 | METHOD AND APPARATUS FOR UPLINK NETWORK MIMO IN A WIRELESS COMMUNICATION SYSTEM - Systems and methodologies are described herein that facilitate generation and processing of control signaling to support uplink network multiple-in-multiple-out (N-MIMO) communication in a wireless communication system. As described herein, respective network nodes associated with an uplink N-MIMO framework can generate channel state information (CSI) corresponding to an uplink channel from a designated network user to the respective nodes. Generated CSI can subsequently be communicated to an uplink anchor node for the network user in order to facilitate rate assignment, scheduling, and/or other operations with respect to the network user. As described herein, CSI generated and reported by respective cells can include channel profiles, carrier/interference profiles, estimated supported uplink rates, or the like. As additionally described herein, supplemental information such as observed interference levels, demodulation indicators, or the like can be communicated to an anchor node and utilized in rate assignment and/or scheduling. | 04-29-2010 |
20100104033 | METHOD AND APPARATUS FOR SEPARABLE CHANNEL STATE FEEDBACK IN A WIRELESS COMMUNICATION SYSTEM - Systems and methodologies are described herein that facilitate the generation and use of separable, hierarchical channel state feedback in a wireless communication system. As described herein, in the event that multiple network nodes cooperate to conduct downlink transmissions to a network user, channel state feedback as reported by the network user can be separated into intra-node feedback relating to per-node channel conditions and inter-node feedback relating to relative phase and/or amplitude between channels corresponding to respective nodes. Further, a network user can select to report intra-node feedback and/or inter-node feedback based on network instructions, a cooperation strategy to be utilized by respective network nodes, or the like. As additionally described herein, respective codebooks on which inter-node and intra-node channel feedback is based can be configured to convey information relating to a partial channel description and/or to vary based on resource units (e.g., sub-bands, resource blocks, etc.) utilized for downlink communication. | 04-29-2010 |
20100105404 | ACKNOWLEDGMENT BASED ON SHORT CELL RADIO NETWORK TEMPORARY IDENTIFIER - Systems and methodologies are described that facilitate identifying resources upon which an acknowledgment can be sent or received in a wireless communication environment that leverages coordinated multi-point (CoMP). The resources can be identified based upon a criterion that can be identifiable to a non-anchor cell base station (as well as an anchor cell base station, a mobile device, etc.). The criterion can be an identifier corresponding to a mobile device, where the identifier maps to a predetermined set of resources. Examples of the identifier can include a media access control identifier (MACID), a cell radio network temporary identifier (C-RNTI), a short C-RNTI, etc. Further, the criterion can be physical resources corresponding to a transmission, where the acknowledgment is responsive to the transmission. Moreover, the acknowledgment can be sent or received in connection with a cooperation technique (e.g., joint transmission via inter-site packet sharing, cooperative beamforming, cooperative silence, . . . ). | 04-29-2010 |
20100106828 | METHOD AND APPARATUS FOR INTERFERENCE REPORTING IN A N-MIMO COMMUNICATION SYSTEM - Systems and methodologies are described herein that facilitate interference measurement and reporting in a network multiple-in-multiple-out (N-MIMO) communication system. As described herein, a network device can measure and report interference corresponding to network nodes outside a designated set of nodes that can cooperatively serve the device. Respective interference reports can additionally identify dominant interfering nodes, correlation between transmit antennas of respective nodes, or the like. Subsequently, respective interference reports can be combined with per-node channel information to manage coordination and scheduling across respective network nodes. As further described herein, interference from a network node can be measured by observing reference and/or synchronization signals from the network node. To aid such observation, respective non-interfering network nodes can define null pilot intervals in which transmission is silenced or otherwise reduced. As additionally described herein, loading information broadcasted by respective interfering network nodes can be identified and utilized in connection with interference calculation. | 04-29-2010 |
20100107028 | METHOD AND APPARATUS FOR H-ARQ SCHEDULING IN A WIRELESS COMMUNICATION SYSTEM - Systems and methodologies are described herein that facilitate Hybrid Automatic Repeat Request (H-ARQ) scheduling and coordination in a wireless communication system. As described herein, a network node capable of cooperation with other nodes for communication to respective users can coordinate a cooperation strategy across nodes based on a H-ARQ protocol to be utilized for a given user. In the case of a synchronous H-ARQ protocol, communication can be scheduled as described herein such that initial transmissions to a user are conducted cooperatively and re-transmissions are conducted without inter-node cooperation. In the case of a H-ARQ protocol utilizing persistent assignments, transmission intervals can be calculated and utilized based on application latency requirements, backhaul link latency, or other factors. In the case of an asynchronous H-ARQ protocol, repeat transmissions can be coordinated in a similar manner to initial transmissions or conducted without inter-node cooperation based on latency sensitivity of an associated application. | 04-29-2010 |
20100142466 | OPTIMIZATION TO SUPPORT UPLINK COORDINATED MULTI-POINT - Systems and methodologies are described that facilitate assigning uplink resources for utilization by a mobile device for sending an uplink signal in an uplink coordinated multi-point (CoMP) wireless communication environment. For instance, a hopping tree can be defined across base stations, and neighboring base stations can schedule interfering mobile devices upon uplink resources mapped to different nodes from the hopping tree. By way of another example, a plurality of hopping trees can be employed across base stations in the uplink CoMP wireless communication environment. Moreover, an acknowledgment can be sent to the mobile device upon downlink resources identified as a function of the uplink resources. Further, the downlink resources can be distinct from disparate downlink resources utilized for sending an acknowledgment to a disparate mobile device from a neighboring base station. | 06-10-2010 |
20100144334 | LIST ELIMINATION FOR DISTRIBUTED DOWNLINK COORDINATED MULTI-POINT (CoMP) FRAMEWORK - Providing for record filtering in distributed dynamic clustering algorithms for coordinated multipoint (CoMP) wireless communication is described herein. By way of example, strategy selection records distributed as part of a belief propagation network are pruned at recipient nodes, thereby reducing processing overhead for dynamic clustering. As a result, cooperative policies can be determined with greater efficiency, and with greater relevance to local clusters of cooperating base stations. In some aspects, record pruning can comprise identifying and discarding redundant or incompatible sets of policy decisions. In at least one aspect, a number of evaluated records can be capped based on relevance, while preserving deployment-wide applicability of the belief propagation network. Accordingly, dynamic distributed CoMP decisions are optimized on a deployment-wide scale that more efficiently converges to maximum utility solutions. | 06-10-2010 |
20100151873 | DYNAMIC CONTROL BLANKING IN HETEROGENEOUS NETWORKS - Systems and methodologies are described that facilitate requesting blanking over control resources from one or more interfering eNBs or devices. An eNB, such as a macrocell, femtocell or picocell eNB, can transmit a downlink control blanking message to a UE directing the UE to perform blanking (e.g., for uplink control resources) or request the blanking from the interfering eNBs or devices (e.g., for downlink control resources). The downlink control blanking message can specify the desired control resources and/or information to determine the control resources. Thus, dynamic control blanking is provided such that blanking is requested to mitigate interference over control resources for the small scale eNB. The small scale eNB can subsequently communicate control data to the UE over the control resources; the control data can include a resource blanking message that similarly directs the UE to request blanking of general data resource from the interfering eNBs or devices. | 06-17-2010 |
20100177746 | SEMI-STATIC RESOURCE ALLOCATION TO SUPPORT COORDINATED MULTIPOINT (COMP) TRANSMISSION IN A WIRELESS COMMUNICATION NETWORK - Techniques for supporting Coordinated MultiPoint (CoMP) transmission are described. For CoMP transmission, multiple cells may simultaneously send one or more data streams to one or more UEs on the same time-frequency resources based on short-term channel feedback from at least one UE to at least two cells. In an aspect, a semi-static configuration may be used by a set of cells for CoMP transmission to a UE. The semi-static configuration may indicate resource elements available to the set of cells to send CoMP transmission to the UE. The available resource elements may be determined based on a maximum number of TDM control symbols for all cells in the set and resource elements used for cell-specific reference signals by the cells in the set. A cell in the set may send data on the available resource elements to the UE for the CoMP transmission. | 07-15-2010 |
20100190447 | DOWNLINK INTERFERENCE CANCELLATION METHODS - A method to mitigate interference in a wireless system is provided. The method includes processing a set of radio network identifiers and limiting a number of hypotheses associated with the radio network identifiers in order to mitigate interference in a wireless network. In another aspect, the method includes processing a set of hypotheses and limiting the set of hypotheses by limiting a number of downlink grants to a common space, limiting the number of downlink grants to a number of instances, or limiting the number of grants to a physical downlink control channel (PDCCH) type. In yet another aspect, the method includes processing a downlink set and generating a target termination level for the downlink data set, the termination level associated with a Hybrid automatic repeat-request. | 07-29-2010 |
20100195527 | SCHEDULING ALGORITHMS FOR COOPERATIVE BEAMFORMING BASED ON RESOURCE QUALITY INDICATION - Certain aspects of the present disclosure support techniques for cooperative beamforming based on inter-cell coordination. Signaling design allows coordinated downlink transmissions with reduced inter-cell interference. | 08-05-2010 |
20100195600 | METHOD AND APPARATUS FOR MULTIPLEXING LEGACY LONG TERM EVOLUTION USER EQUIPMENT WITH ADVANCED LONG TERM EVOLUTION USER EQUIPMENT - Aspects are disclosed for multiplexing disparate wireless terminals. Resource blocks are mapped according to a hopping pattern. A first and second pair of physical resource blocks are allocated such that the first pair is associated with a first hopping index pair, whereas the second pair is associated with a second hopping index pair. For this embodiment, the first and second hopping index pairs are inversely symmetrical to each other. A pair of distributed resource blocks is also allocated. An assignment is then scheduled that includes a physical resource allocation and a virtual resource allocation. Aspects for operating a wireless terminal are also disclosed. Here, a communication that includes a resource allocation and a reference signal is received. A minimum resource allocation granularity is ascertained from the communication, and a joint channel estimation is based on the reference signal and is a function of the minimum resource allocation granularity. | 08-05-2010 |
20100202308 | SCHEDULING ALGORITHMS FOR COOPERATIVE BEAMFORMING - Certain aspects of the present disclosure support techniques for cooperative beamforming based on inter-cell coordination. Signaling design allows coordinated downlink transmissions with reduced inter-cell interference. | 08-12-2010 |
20100202561 | METHOD AND APPARATUS FOR MODULATION AND LAYER MAPPING IN A WIRELESS COMMUNICATION SYSTEM - Systems and methodologies are described herein that facilitate improved modulation and coding techniques for a multiple-in multiple-out (MIMO) communication system. As described herein, data to be transmitted over a set of physical layers (e.g., corresponding to antennas, beams, etc.) can be processed such that encoding is performed on a per-codeword basis and modulation is performed on a per-layer basis, thereby mitigating performance degradation experienced by traditional systems due to layer imbalance. As further described herein, per-codeword code rate parameters and per-layer modulation parameters can be signaled to a device in various manners, such as through modulation and coding scheme (MCS) signaling, explicit code rate and/or modulation scheme signaling, relative code rate and/or modulation scheme signaling, or the like. | 08-12-2010 |
20100232384 | CHANNEL ESTIMATION BASED UPON USER SPECIFIC AND COMMON REFERENCE SIGNALS - Systems and methods are disclosed to facilitate wireless communications. The systems and methods include generating one or more user specific reference signals (UE-RS) and one or more common reference signals (CRS) at a transmitting node; transmitting the UE-RS and the CRS to a user (UE) using a transmission scheme in accordance with a mapping function to enable the UE to estimate a channel based upon CRS observations, UE-RS observations, and the mapping function; and transmitting data using the transmission scheme in accordance with the mapping function. | 09-16-2010 |
20100265913 | INTER-FREQUENCY INDICATION OF ASSOCIATION DATA FOR MULTI-CARRIER WIRELESS DEPLOYMENTS - Providing for user equipment mobility in a multi-carrier wireless network deployment is described herein. By way of example, data pertinent to mobile cell selection can be shared among base stations operating on different carrier frequencies either over-the-air or via a wired backhaul, and distributed by a base station to mobile terminals served by the base station. In one aspect, the data can be distributed over a wireless channel reserved for inter-carrier association data, whereas in other aspects, the data can be unicast to particular mobile terminals served by the base station. This can reduce or avoid a need for individual mobile terminals to tune away to a non-serving carrier for inter-carrier association or handover determinations. Accordingly, gaps in signal analysis on a serving carrier can be reduced or avoided, improving overall quality of wireless communication in a multi-carrier environment. | 10-21-2010 |
20100309861 | INTERFERENCE MITIGATION FOR DOWNLINK IN A WIRELESS COMMUNICATION SYSTEM - Techniques for mitigating interference in a wireless communication system are described. In an aspect, pertinent transmission parameters for a served UE may be sent to at least one interfered UE to support interference mitigation. In one design, information for at least one transmission parameter for a data transmission sent by a first cell to a first UE may be transmitted to at least one UE served by a second cell to enable the at least one UE to perform interference mitigation for the data transmission sent by the first cell to the first UE. The information may be transmitted by either the first cell or the second cell. In another aspect, a cell may send transmission parameters for a UE via a pilot. In yet another aspect, scrambling may be performed by a cell at symbol level to enable an interfered UE to distinguish between modulation symbols of desired and interfering transmissions. | 12-09-2010 |
20100330946 | ENHANCED INTERFERENCE NULLING EQUALIZATION - Systems and methodologies are described that facilitate combining received signals from multiple receive antennas in a wireless communication environment. The received signals from the multiple receive antennas can be weighted utilizing an adaptive combination of maximal ratio combining (MRC) and interference nulling. The combination of MRC and interference nulling can be controlled based upon one or more configurable parameters. For instance, a covariance matrix can be modified to include the one or more configurable parameters, and the modified covariance matrix can be utilized in connection with interference nulling. Further, respective values for the one or more configurable parameters can be selected as a function of at least one input (e.g., measured interference-over-thermal (IoT) value, received loading level indicator, eigenvalue distribution of a covariance matrix, . . . ) related to noise correlation. | 12-30-2010 |
20110086663 | SELECTIVE TRANSMISSION OF POWER DECISION PILOT IN A WIRELESS COMMUNICATION SYSTEM - Techniques for selectively transmitting a power decision pilot are described. The power decision pilot may be indicative of the transmit power to use for data transmission in a future time interval. The power decision pilot may be transmitted when sufficiently beneficial for channel quality estimation or omitted otherwise. Whether or not to transmit the power decision pilot may be determined based on system type (e.g., heterogeneous or homogeneous system), the presence or absence of a dominant interferer, whether a reduce interference request is received, etc. For example, a base station may transmit a power decision pilot if it causes high interference to a non-served terminal, if a served terminal observes high interference from a neighbor base station, if the base station receives a reduce interference request from a non-served terminal, etc. The power decision pilot may be transmitted if a determination is made to transmit the pilot or omitted otherwise. | 04-14-2011 |
20110098054 | SOUNDING REFERENCE SIGNAL FOR COORDINATED MULTI-POINT OPERATION - Systems and methodologies are described that facilitate configuring a sounding reference signal transmission in a wireless communication environment. A UE can employ coordinated multi-point transmission and/or reception such that multiple cells collaborate to transmit data to the UE and/or receive data from the UE. To support the coordinated multi-point transmission and/or reception, the UE can transmit a sounding reference signal that is configured to enable reliable reception of the sounding reference signal by members of a cooperating set. In addition, configuration of the sounding reference signal can be coordinated to enable more efficient transmission and utilization of the sounding reference signal. Configuration of the sounding reference signal can be based upon information exchanged between the multiple cells. Moreover, the multiple cells can coordinate to set and control a transmit power of the sounding reference signal. | 04-28-2011 |
20110158164 | SYSTEMS AND METHODS FOR JOINT PROCESSING IN A WIRELESS COMMUNICATION - A method, an apparatus, and a computer program product for wireless communication are provided in which signals are received from a plurality of base stations, and a measurement is made of synchronization parameters between the plurality of base stations at a user equipment. A signal is transmitted from the user equipment to at least one of the plurality of base stations with information about the synchronization parameters. The base station determines an offset in the received synchronizations and adjusts a transmission waveform based on the determined offset. | 06-30-2011 |
20110158351 | METHOD AND APPARATUS FOR COMMUNICATING ANTENNA PORT ASSIGNMENTS - A method, an apparatus, and a computer program product for wireless communication are provided in which downlink control information (DCI) including a total number of available antenna ports, a rank indicator for a user equipment (UE), and one or more port assignment bits is received, a subset of the total number of available antenna ports that are assigned to the UE based on at least one of: the rank indicator or the one or more port assignment bits is determined, and demodulation based on reference signals corresponding to the set of assigned antenna ports is performed. | 06-30-2011 |
20110206106 | HIERARCHICAL FEEDBACK OF CHANNEL STATE INFORMATION FOR WIRELESS COMMUNICATION - Techniques for sending hierarchical feedback of channel state information are described. In one design, a user equipment (UE) determines channel gain information for multiple cells selectable to transmit data to the UE. The UE also determines intra-cell relative phase information for at least one cell among the multiple cells. The UE reports the channel gain information and the intra-cell relative phase information. The channel gain information may include multiple quantized channel vectors for each of the multiple cells. The intra-cell relative phase information may indicate phase errors in the quantized channel vectors for each of the at least one cell. The UE may also determine and report other information. The UE may receive data from one or more cells among the plurality of cells. Each cell may transmit data based on at least one transmit vector determined based on the channel gain information and the intra-cell relative phase information. | 08-25-2011 |
20110268007 | COORDINATED MULTI-POINT (CoMP) NETWORK AND PROTOCOL ARCHITECTURE - Aspects of the present disclosure relate generally to wireless communication systems, and more particularly to a coordinated multi-point network and protocol architecture. One aspect discloses a method of wireless communication and includes receiving a measurement report from a user equipment (UE). Coordinated multi point (CoMP) control messages are transmitted from a first eNodeB to a second eNodeB at a medium access control (MAC) layer in response to the received measurement report. | 11-03-2011 |
20120071193 | REVERSE LINK TRAFFIC POWER CONTROL - Systems and methodologies are described that facilitate reverse link power control on a traffic channel. Indications of other sector interference or other such interference levels can be broadcasted in a wireless communication. Further, power control related information can be included in assignments to mobile devices. Mobile device can utilize the information in the assignment to set a range for delta-based power control. Further, devices employ broadcasted interference indications to maintain and adjust delta values that enable power settings to be established on traffic channels. Moreover, mobile devices may provide feedback to facilitate future assignments. | 03-22-2012 |
20120287859 | SERVING BASE STATION SELECTION IN A WIRELESS COMMUNICATION NETWORK - Techniques for selecting a serving base station for a terminal in a wireless communication network are described. In one design, multiple candidate base stations for the terminal may be identified, with each candidate base station being a candidate for selection as the serving base station for the terminal. The multiple candidate base stations may include base stations with different transmit power levels and/or may support interference mitigation. One of the multiple candidate base stations may be selected as the serving base station. In one design, the serving base station may be selected based on at least one metric for each candidate base station. The at least one metrics may be for pathloss, effective transmit power, effective geometry, projected data rate, control channel reliability, network utility, etc. The selected candidate base station may have a lower SINR than a highest SINR among the multiple candidate base stations. | 11-15-2012 |
20130136062 | METHOD AND APPARATUS FOR SEPARABLE CHANNEL STATE FEEDBACK IN A WIRELESS COMMUNICATION SYSTEM - Systems and methodologies are described herein that facilitate the generation and use of separable, hierarchical channel state feedback in a wireless communication system. As described herein, in the event that multiple network nodes cooperate to conduct downlink transmissions to a network user, channel state feedback as reported by the network user can be separated into intra-node feedback relating to per-node channel conditions and inter-node feedback relating to relative phase and/or amplitude between channels corresponding to respective nodes. Further, a network user can select to report intra-node feedback and/or inter-node feedback based on network instructions, a cooperation strategy to be utilized by respective network nodes, or the like. As additionally described herein, respective codebooks on which inter-node and intra-node channel feedback is based can be configured to convey information relating to a partial channel description and/or to vary based on resource units (e.g., sub-bands, resource blocks, etc.) utilized for downlink communication. | 05-30-2013 |
20130196603 | FLEXIBLE RADIO RESOURCE MANAGEMENT (RRM) MEASUREMENTS FOR WIRELESS NETWORKS - Methods and apparatus for performing reference signal (RS) metric measurements in different parts of a channel bandwidth are described. One example method generally includes receiving signaling indicating one or more frequency bands within an operating frequency band of a current serving cell for performing reference signal (RS) metric measurements, performing the measurements on the one or more frequency bands, and reporting the measurements. | 08-01-2013 |
20130219055 | METHOD AND APPARATUS FOR INTERFERENCE REPORTING IN A N-MIMO COMMUNICATION SYSTEM - Systems and methodologies are described herein that facilitate interference measurement and reporting in a network multiple-in-multiple-out (N-MIMO) communication system. As described herein, a network device can measure and report interference corresponding to network nodes outside a designated set of nodes that can cooperatively serve the device. Respective interference reports can additionally identify dominant interfering nodes, correlation between transmit antennas of respective nodes, or the like. Subsequently, respective interference reports can be combined with per-node channel information to manage coordination and scheduling across respective network nodes. As further described herein, interference from a network node can be measured by observing reference and/or synchronization signals from the network node. To aid such observation, respective non-interfering network nodes can define null pilot intervals in which transmission is silenced or otherwise reduced. As additionally described herein, loading information broadcasted by respective interfering network nodes can be identified and utilized in connection with interference calculation. | 08-22-2013 |
20130229935 | METHOD AND APPARATUS FOR COOPERATION STRATEGY SELECTION IN A WIRELESS COMMUNICATION SYSTEM - Systems and methodologies are described that facilitate cooperation strategy selection for a network multiple-in-multiple-out (N-MIMO) communication system. As described herein, one or more nodes in a communication system capable of N-MIMO communication can calculate marginal utilities, projected per-user rates, and/or other parameters corresponding to respective associated users. Based on these calculations, respective network nodes can perform user scheduling and selection, cell scheduling and selection, selection of a cooperation strategy (e.g., coordinated silencing, joint transmission, coordinated beamforming, etc.), and/or other operations to provide cooperative communication for respective users. As further described herein, projected rate calculation for a given user can be adjusted based on processing or channel implementation loss associated with the user, interference nulling capability of the user, or other factors. As additionally described herein, these and/or other parameters can be fed back by respective users to a serving network node and/or mandated via system performance requirements. | 09-05-2013 |
20130294275 | DISTRIBUTED DOWNLINK COORDINATED MULTI-POINT (CoMP) FRAMEWORK - Systems and methodologies are described that facilitate dynamically forming clusters in a wireless communication environment. A set of non-overlapping clusters can be formed dynamically over time and in a distributed manner. Each of the clusters can include a set of base stations and a set of mobile devices. The clusters can be yielded based upon a set of local strategies selected by base stations across the network converged upon through message passing. For example, each base station can select a particular local strategy as a function of time based upon network-wide utility estimates respectively conditioned upon implementation of the particular local strategy and disparate possible local strategies that can cover the corresponding base station. Moreover, operation within each of the clusters can be coordinated. | 11-07-2013 |
20140185540 | ENB PDCCH IMPLEMENTATION TO AVOID AMBIGUOUS DCI INFORMATION - A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus determines a first decoding candidate in a first search space and a second decoding candidate in a second search space, where the first decoding candidate and the second decoding candidate have a same size but different definitions of information fields, identifies a difference in the information fields, and determines one of the first decoding candidate and the second decoding candidate as a valid candidate based on the identified difference. The apparatus further generates first control information for transmitting in a first search space, codes the first control information, wherein the code applied to the first control information is specific to the first search space and different from code applied to second control information in a second search space, and transmits the coded first control information in the first search space. | 07-03-2014 |
20140185541 | ENB PDCCH IMPLEMENTATION TO AVOID AMBIGUOUS DCI INFORMATION - A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus determines a first starting index for transmitting first control information in a first search space, determines a second starting index for transmitting second control information in a second search space, and transmits the second control information in the second search space at the second starting index when the first starting index and the second starting index are not the same value. The apparatus further transmits to a user equipment (UE) control information in a first search space, receives information from the UE corresponding to the transmitted control information, and decodes the received information based on the UE parsing the control information according to the first search space and based on the UE incorrectly parsing the control information according to a second search space. | 07-03-2014 |
20150023259 | MULTI-CARRIER OPERATION IN A WIRELESS COMMUNICATION NETWORK - Techniques for communicating on multiple carriers in a wireless communication network are described. In an aspect, different transmit power levels may be used for different carriers to mitigate interference. A first base station may be assigned one or more carriers among multiple carriers available for communication. A second base station may be assigned one or more carriers not assigned to the first base station. Each base station may communicate on each assigned carrier at a first (e.g., full) transmit power level and may communicate on each unassigned carrier at a second (e.g., lower) transmit power level lower. The first and second base stations may belong in different power classes or support different association types. In another aspect, control information may be sent on a designated carrier to support communication on multiple carriers. In yet another aspect, a base station may broadcast bar information indicating the status of carriers. | 01-22-2015 |
20150055611 | METHOD AND APPARATUS FOR MITIGATING PILOT POLLUTION IN A WIRELESS NETWORK - Techniques for mitigating pilot pollution in a wireless network are described. In an aspect, pilot pollution may be mitigated by reducing density and/or transmit power of common pilots whenever possible. A cell may send a common pilot at a first density and a first transmit power level during a first time period and may send the common pilot at a second density and a second transmit power level during a second time period. The second density may be lower than the first density and/or the second transmit power level may be lower than the first transmit power level. Lower density may be achieved by sending the common pilot less frequently, on fewer subcarriers, and/or from fewer antennas. The cell may determine whether to reduce the density and/or transmit power of the common pilot based on network loading, SINRs of terminals, etc. In another aspect, pilot pollution may be mitigated by performing pilot cancellation at a terminal. | 02-26-2015 |