| Patent application number | Description | Published |
|---|
| 20080279170 | METHOD AND APPARATUS FOR MULTIPLEXING CDM PILOT AND FDM DATA - Techniques for sending control information in a wireless communication system are described. In an aspect, a user equipment (UE) may send data for control information in a resource block with frequency division multiplexing (FDM) and may send pilot in the resource block with frequency-domain code division multiplexing (CDM). The UE may determine multiple groups of subcarriers to use to send data in multiple symbol periods of the resource block based on a predetermined pattern or a pseudo-random hopping pattern. Each group may include consecutive subcarriers to support localized FDM. The multiple groups may include different subcarriers to provide frequency diversity and possibly interference averaging. The UE may send modulation symbols for data (e.g., in the time domain) on the multiple groups of subcarriers in the multiple symbol periods. The UE may send a reference signal sequence for pilot on multiple subcarriers in each symbol period for pilot. | 11-13-2008 |
| 20080287155 | MULTIPLEXING AND POWER CONTROL OF UPLINK CONTROL CHANNELS IN A WIRELESS COMMUNICATION SYSTEM - Techniques for transmitting control information in a wireless communication system are described. The system may support acknowledgement (ACK) channels and channel quality indicator (CQI) channels, which may have different target signal-to-noise ratios (SNRs). The ACK and CQI channels from different user equipments (UEs) may be multiplexed on the same resource block. In one design, the transmit power of a CQI channel may be set to achieve a nominal target SNR for CQI when not multiplexed with the ACK channels and may be reduced to achieve a lower target SNR when multiplexed with the ACK channels. In another design, the transmit power of an ACK channel may be set to achieve a nominal target SNR for ACK when not multiplexed with the CQI channels and may be boosted to achieve a higher target SNR when multiplexed with the CQI channels. The CQI channel may randomly hop to mitigate performance degradation. | 11-20-2008 |
| 20080298502 | PILOT STRUCTURES FOR ACK AND CQI IN A WIRELESS COMMUNICATION SYSTEM - Techniques for transmitting data and pilot for control information are described. In one aspect, a user equipment (UE) may spread a reference signal sequence with a first orthogonal sequence to obtain multiple pilot sequences. The UE may then send the multiple pilot sequences on multiple subcarriers in multiple symbol periods, one pilot sequence in each symbol period. The UE may modulate the reference signal sequence with control information (e.g., ACK information) to obtain a modulated sequence. The UE may spread the modulated sequence with a second orthogonal sequence to obtain multiple data sequences. The UE may then send the multiple data sequences on the multiple subcarrier in multiple symbol periods for data. In another aspect, the UE may send multiple pilot sequences on multiple subcarriers in multiple symbol periods separated by at least one symbol period, one pilot sequence in each symbol period. | 12-04-2008 |
| 20090046800 | FEEDBACK AND RATE ADAPTATION FOR MIMO TRANSMISSION IN A TIME DIVISION DUPLEXED (TDD) COMMUNICATION SYSTEM - Techniques for sending a MIMO transmission in a wireless communication system are described. In one design, a transmitter sends a first reference signal to a receiver. The receiver selects a precoding matrix based on the first reference signal and in accordance with a selection criterion. The receiver estimates noise and interference at the receiver and determines channel quality indicator (CQI) or modulation and coding scheme (MCS) information based on the precoding matrix and the estimated noise and interference. The receiver sends the CQI or MCS information and a second reference signal to the transmitter. The transmitter selects the precoding matrix based on the second reference signal and in accordance with the same selection criterion used by the receiver. The transmitter then sends a MIMO transmission to the receiver based on the CQI or MCS information obtained from the receiver and the precoding matrix selected by the transmitter. | 02-19-2009 |
| 20090141690 | METHOD AND APPARATUS FOR UPLINK CONTROL SIGNALING - A transmitter in a wireless network transmits joint channel quality indicator (CQI) and data packet acknowledgement (Ack) or just CQI within the same subframe without uplink data transmission that can be readily detected at a receiver. When a short cyclic prefix (CP) is appropriate, a first approach utilizes a pilot aided signaling by using two different Walsh covers for the pilots to signal CQI vs. CQI+ACK. When a long CP is appropriate with one pilot, two different code designs are provided for CQI and CQI+ACK that only optimize the code book for each mode separately, but also maximize the distance between these two code spaces. Various coset based approaches are described to search for such linear block codes. Initial results showed good codes can be found based on the coset based approach to minimize the false alarm and misdetection. | 06-04-2009 |
| 20090196247 | SIMULTANEOUS TRANSMISSION OF ACKNOWLEDGEMENT, CHANNEL QUALITY INDICATOR AND SCHEDULING REQUEST - Systems and methodologies are described that facilitate simultaneous transmission of control information in a single sub-frame. For instance, simultaneous transmission can maintain single carrier waveforms for a control channel even when a plurality of information types is scheduled in concurrently. Channel quality indicators, scheduling requests and acknowledgement messages can be jointly coded. In addition, reference symbols in a sub-frame can be modulated to indicate values associated with a scheduling request or an acknowledgement message. Moreover, in situations where channel quality indicators, scheduling requests and or acknowledgement messages are simultaneously scheduled, one or more can be dropped. Further, a single carrier constraint can be relaxed to enable simultaneous transmission of information in the sub-frame at different frequencies. | 08-06-2009 |
| 20090201869 | ENHANCED MULTIPLEXING SYSTEM AND TECHNIQUE FOR UPLINK CONTROL CHANNELS - A communication system incorporates a multiplexing scheme so that a base node that schedules user equipment (UE) can determine whether an ACK/NACK and/or a service request (SR) has been received when both uplink (UL) transmissions are simultaneously scheduled. Significant complexity reduction, better link efficiency, and higher multiplexing capability since the base node can interpret selective use by the UE of either the ACK/NACK or SR UL channel. Such interpretation can be extended to when multiple downlink (DL) transmission modes can be used, specifically DL single input multiple output (SIMO), DL multiple input multiple output (MIMO) with rank | 08-13-2009 |
| 20090221289 | DISCONTINUOUS TRANSMISSION SIGNALING OVER AN UPLINK CONTROL CHANNEL - Systems and methodologies are described that facilitate signaling and detecting discontinuous transmission (DTX) in a wireless communication environment. A DTX indicator and Channel Quality Indicator (CQI) feedback can be multiplexed within a common uplink control channel subframe and transmitted to a base station when the access terminal is operating in DTX mode for an Acknowledgement Channel. Further, when operating in non-DTX mode, the access terminal can multiplex an ACK indicator or a NAK indicator with the CQI feedback within a common uplink control channel subframe, which can thereafter be transferred to the base station. Accordingly, the base station can detect DTX operation or non-DTX operation of the access terminal. For example, reference signal symbols can carry one of the DTX indicator, the ACK indicator, or the NAK indicator. Pursuant to another example, the CQI feedback and the DTX indicator can be combined and carried jointly by non-reference signal symbols. | 09-03-2009 |
| 20090245284 | ENCODING AND DECODING OF CONTROL INFORMATION FOR WIRELESS COMMUNICATION - Techniques for sending control information in a wireless communication system are described. In one design, a user equipment (UE) may map first information (e.g., CQI information) to M most significant bits (MSBs) of a message and may map second information (e.g., ACK information) to N least significant bits (LSBs) of the message if the second information is sent, where M≧1 and N≧1. The UE may encode the message with a block code, e.g., encode the M MSBs with the first M basis sequences of the block code and encode the N LSBs with the next N basis sequences of the block code. The second information may include N ACK bits. The UE may set each ACK bit to a first value for an ACK or to a second value for a NACK. The second value may also be used for discontinuous transmission (DTX) of ACK information. | 10-01-2009 |
| 20090296850 | ENCODED CONTROL CHANNEL INFORMATION INTERLEAVING - Systems and methodologies are described that facilitate interleaving encoded control channel information for transmission over an uplink channel. The encoded control channel information, for example, can include encoded Channel Quality Indicator (CQI) information, encoded Precoding Matrix Indicator (PMI) information, and/or Rank Indicator (RI) information. CQI information, PMI information, and/or RI information can be encoded at an access terminal, for instance, by applying a punctured Reed Muller block code to generate a sequence of encoded bits. The encoded bits can be interleaved to reorder the sequence utilizing one or more interleaving approaches. Examples of interleaving approaches that can be leveraged include prime number based interleaving, generalized bit reversal interleaving, column-row interleaving with column bit reversal, and/or M-sequence based interleaving. Further, the reordered sequence of encoded bits can be transmitted to a base station over an uplink channel. | 12-03-2009 |
| 20100029320 | Methods and apparatus for power allocation and/or rate selection for UL MIMO/SIMO operations with PAR considerations - A method for a wireless communication includes receiving or storing a peak to average (PAR) back off value; and applying the PAR back off value to determine the transmission power and rate for SIMO and MIMO transmissions. In one aspect, the PAR back off value is at least partially based on modulation type. In another aspect, the PAR back off value is more for higher order QAM than for QPSK. The power allocation algorithm for different UL MIMO schemes is described as follows. For MIMO without antenna permutation (e.g. per antenna rate control), different PAR back off values are considered for different data streams. For MIMO with antenna permutation or other unitary transformation such as virtual antenna mapping or precoding, the PAR back off are determined based on combined channel. The transmission data rate depends on power and also the receiver algorithms such as a MMSE receiver or MMSE-SIC receiver. | 02-04-2010 |
| 20100050039 | HANDLING OF DISRUPTED SYNCHRONOUS HYBRID AUTOMATIC REPEAT REQUEST (HARQ) CYCLE AT SYSTEM TIME ROLLOVER - Certain aspects of the present disclosure propose techniques for avoiding a disruption in synchronous hybrid automatic repeat request operation at system time rollover. The techniques define the behavior of a system before and after the system frame number (SFN) rollover point to ensure a known relationship between a hybrid automatic repeat request (HARQ) process identification number and system time. | 02-25-2010 |
| 20100054371 | Noise Variance Estimation In Wireless Communications For Diversity Combining and Log Likelihood Scaling - The present patent application comprises a method and means for demodulating symbols, comprising converting an OFDM symbol from a time domain to a frequency domain, selecting pilot tones, making a soft decision based on received data, and estimating a channel frequency response. In another example, the method and means further comprises selecting guard tones. In another example, the method and means further comprises generating channel estimates for in-band and band-edge pilot tones. | 03-04-2010 |
| 20100091702 | Cell search based on beacon in a wireless communication system - Techniques for transmitting beacon signals to assist user equipments (UEs) perform cell search and techniques for detecting for beacon signals are described. In an aspect, cells may be assigned beacon patterns defined based on orthogonal grouping of subcarriers. U subcarriers usable for beacon may be arranged into G orthogonal groups, with each group including S subcarriers. different beacon patterns may be defined based on the G groups of S subcarriers. In another aspect, the cells may transmit their beacon signals at configurable transmit power levels, which may be determined based on target beacon detection performance. In yet another aspect, a UE may perform overlapping DFTs in order to capture more received power when symbol timing at the UE is not aligned with symbol timing of cells being detected. In yet another aspect, the UE may perform beacon detection with maximal likelihood decoding. | 04-15-2010 |
| 20100091919 | Joint use of multi-carrier and single-carrier multiplexing schemes for wireless communication - A communication system that facilitates transmissions in accordance with a single-carrier (SC) multiplexing scheme, a multi carrier (MC) multiplexing scheme or a combination thereof is disclosed. Based on various factors such as attributes associated with a UE (user equipment) or availability of resources, a base station can signal to the UE an appropriate multiplexing scheme to be adopted for particular transmissions. The UE can be scheduled for transmission in a semi-static mode wherein the UE employs the transmission scheme for a particular time interval or it may change the mode dynamically for different transmissions. For transmissions from the UE comprising a plurality of data streams with dissimilar attributes, the base station implements a MIMO (multiple input multiple output) system for the UE. This facilitates a UE to dynamically switch between or simultaneously adopt the various multiplexing schemes for communications and thereby fully utilize advantages associated with the different schemes. | 04-15-2010 |
| 20100232311 | CONCURRENT TRANSMISSION OF ACK/NACK, CQI AND CQI FROM USER EQUIPMENT - A wireless communications method is provided. The method includes providing a multi-codeword transmission that includes ACK/NACK and discontinuous transmission (DTX) information. The method also includes ordering reference signal (RS) symbols in proximity to at least one other reference signal symbol to facilitate signaling of additional states and enabling spreading gain to be increased. | 09-16-2010 |
| 20100296591 | UNIFIED DESIGN AND CENTRALIZED SCHEDULING FOR DYNAMIC SIMO, SU-MIMO AND MU-MIMO OPERATION FOR RL TRANSMISSIONS - Systems and methods facilitate pilot signal design, power control, data rate determination, and channel assignment in the reverse link of a wireless communication system for dynamic scheduling and joint operation in SIMO, SU-MIMO, and MU-MIMO. Pilot signal is based on periodic transmissions of multiple sounding reference sequences for channel estimation. Power control is based on a reference signal at a predetermined power spectral density (PSD) level, and on an offset PSD determined and QC signaled based on an antenna that transmits the reference signal, other cell interference, and power amplifier headroom. PSD levels for SIMO/MIMO data transmissions are determined based on channel estimates and the predetermined PSD and offset PSD. Such data PSD levels are employed to generate data rates, and to dynamically schedule data streams for communication. Communication resources are conveyed through a channel assignment with an overhead that depends on the maximum multiplexing order of the estimated channel. | 11-25-2010 |
| 20110019529 | INTERFERENCE SUPPRESSION IN UPLINK ACKNOWLEDGEMENT - The present disclosure proposes design of a pico/femto uplink acknowledgement (ACK) channel that improves the interference suppression for pico/femto base stations. The proposed design provides a two-layered cell-separation ACK channel structure for femto/pico cells by using computer generated sequences (CGS) and Discrete Fourier Transform (DFT) spreading. Thereby, ACK channels may be multiplexed across different femto/pico base stations with minimal interference. The proposed scheme is compatible with conventional standards for the base station in the macro cell and does not impose any changes on the macro cell. | 01-27-2011 |
| 20110032838 | MITIGATION OF CRS MISALIGNMENT IN COORDINATED MULTIPOINT COMMUNICATIONS - Certain aspects of the present disclosure relate to a method for coordinated multipoint wireless communications. A technique for joint processing of misaligned reference signals in coordinated multipoint communications is provided. In one aspect, a cell may transmit an offsetting reference signal which, when processed by a receiving user equipment, at least partially cancels a first reference signal transmitted by the cell. | 02-10-2011 |
| 20110038328 | METHOD AND APPARATUS THAT FACILITATES INTERFERENCE CANCELLATION FOR CONTROL CHANNELS IN HETEROGENOUS NETWORKS - Aspects are described for reducing interference in wireless systems. In a first embodiment, an uplink acknowledgment region associated with a macro cell is determined, and an assignment of uplink control resources is restricted to a region within the uplink acknowledgment region. A control signal is then transmitted to user equipment via the assignment of uplink control resources. In another embodiment, control signals are received from wireless terminals, which include desired uplink control signals associated with an access point base station, as well as interfering uplink acknowledgement signals associated with macro cells. The control signals may then be regenerated by cancelling the set of interfering signals from the control signals. The desired uplink control signals are then decoded. | 02-17-2011 |
| 20110044269 | METHODS AND APPARATUS FOR BLIND INTERFERENCE DECREASE/CANCELLATION TECHNIQUES - A method, an apparatus, and a computer program product for wireless communication are provided in which one or more semi-static parameters associated with at least one neighboring eNode B (eNB) and an interfering user equipment (UE) are detected, at an eNB, and a blind interference reduction scheme based on the one or more detected semi-static parameters to reduce a signal from the interfering UE is applied. | 02-24-2011 |
| 20110141971 | MECHANISMS FOR INFORMATION EXCHANGE ACROSS CELLS TO FACILITATE RECEPTION IN A HETEROGENEOUS NETWORK - A method, an apparatus, and a computer program product for wireless communication are provided in which a signal including a signal from a UE is received. System information of a neighboring eNodeB is obtained. The received signal is processed based on the system information in order to enhance the received signal with respect to the signal from the UE. | 06-16-2011 |
| 20110142115 | METHOD AND APPARATUS THAT FACILITATES ESTIMATING DOPPLER SPREAD FOR UPLINK TRANSMISSIONS - Methods, apparatuses, and computer program products are disclosed for performing a Doppler spread estimation. In a first embodiment, an energy associated with a communication from a wireless terminal is ascertained based on at least one pilot symbol and at least one data symbol. Each of an energy variance and a noise variance are then determined to facilitate estimating a speed of the wireless terminal based on the energy variance normalized by the noise variance. In another embodiment, a signal received from a wireless terminal is decoded and replicated. A channel estimate associated with a set of data symbols is then ascertained from the replica, which is used to estimate the speed of the wireless terminal. | 06-16-2011 |
| 20110143762 | SYSTEMS, APPARATUS AND METHODS FOR PHYSICAL RANDOM ACCESS CHANNEL PROCESSING - Systems and methods for processing a physical random access channel are provided. In some embodiments, a method can include: receiving a signal indicative of a strong user and a desired user on a physical random access channel; performing at least one of a single segment frequency domain detection or a multi-segment frequency domain detection on the signal indicative of a strong user and a desired user; generating a residual signal by cancelling out the signal indicative of a strong user; and obtaining a message transmitted by a user equipment by performing at least one of the single segment frequency domain detection or multi-segment frequency domain detection on the residual signal. | 06-16-2011 |
