Patent application number | Description | Published |
20080212657 | ITERATIVE DETECTION AND DECODING FOR A MIMO-OFDM SYSTEM - Techniques to iteratively detect and decode data transmitted in a wireless (e.g., MIMO-OFDM) communication system. The iterative detection and decoding is performed by iteratively passing soft (multi-bit) “a priori” information between a detector and a decoder. The detector receives modulation symbols, performs a detection function that is complementary to the symbol mapping performed at the transmitter, and provides soft-decision symbols for transmitted coded bits. “Extrinsic information” in the soft-decision symbols is then decoded by the decoder to provide its extrinsic information, which comprises the a priori information used by the detector in the detection process. The detection and decoding may be iterated a number of times. The soft-decision symbols and the a priori information may be represented using log-likelihood ratios (LLRs). Techniques are provided to reduce the computational complexity associated with deriving the LLRs, including interference nulling to isolate each transmitted signal and “dual-maxima” approximation. | 09-04-2008 |
20080267098 | MIMO SYSTEM WITH MULTIPLE SPATIAL MULTIPLEXING MODES - A MIMO system supports multiple spatial multiplexing modes for improved performance and greater flexibility. These modes may include (1) a single-user steered mode that transmits multiple data streams on orthogonal spatial channels to a single receiver, (2) a single-user non-steered mode that transmits multiple data streams from multiple antennas to a single receiver without spatial processing at a transmitter, (3) a multi-user steered mode that transmits multiple data streams simultaneously to multiple receivers with spatial processing at a transmitter, and (4) a multi-user non-steered mode that transmits multiple data streams from multiple antennas (co-located or non co-located) without spatial processing at the transmitter(s) to receiver(s) having multiple antennas. For each set of user terminal(s) selected for data transmission on the downlink and/or uplink, a spatial multiplexing mode is selected for the user terminal set from among the multiple spatial multiplexing modes supported by the system. | 10-30-2008 |
20080267138 | MIMO SYSTEM WITH MULTIPLE SPATIAL MULTIPLEXING MODES - A MIMO system supports multiple spatial multiplexing modes for improved performance and greater flexibility. These modes may include (1) a single-user steered mode that transmits multiple data streams on orthogonal spatial channels to a single receiver, (2) a single-user non-steered mode that transmits multiple data streams from multiple antennas to a single receiver without spatial processing at a transmitter, (3) a multi-user steered mode that transmits multiple data streams simultaneously to multiple receivers with spatial processing at a transmitter, and (4) a multi-user non-steered mode that transmits multiple data streams from multiple antennas (co-located or non co-located) without spatial processing at the transmitter(s) to receiver(s) having multiple antennas. For each set of user terminal(s) selected for data transmission on the downlink and/or uplink, a spatial multiplexing mode is selected for the user terminal set from among the multiple spatial multiplexing modes supported by the system. | 10-30-2008 |
20080285488 | MIMO WLAN SYSTEM - A multiple-access MIMO WLAN system that employs MIMO, OFDM, and TDD. The system (1) uses a channel structure with a number of configurable transport channels, (2) supports multiple rates and transmission modes, which are configurable based on channel conditions and user terminal capabilities, (3) employs a pilot structure with several types of pilot (e.g., beacon, MIMO, steered reference, and carrier pilots) for different functions, (4) implements rate, timing, and power control loops for proper system operation, and (5) employs random access for system access by the user terminals, fast acknowledgment, and quick resource assignments. Calibration may be performed to account for differences in the frequency responses of transmit/receive chains at the access point and user terminals. The spatial processing may then be simplified by taking advantage of the reciprocal nature of the downlink and uplink and the calibration. | 11-20-2008 |
20080285669 | MIMO WLAN SYSTEM - A multiple-access MIMO WLAN system that employs MIMO, OFDM, and TDD. The system (1) uses a channel structure with a number of configurable transport channels, (2) supports multiple rates and transmission modes, which are configurable based on channel conditions and user terminal capabilities, (3) employs a pilot structure with several types of pilot (e.g., beacon, MIMO, steered reference, and carrier pilots) for different functions, (4) implements rate, timing, and power control loops for proper system operation, and (5) employs random access for system access by the user terminals, fast acknowledgment, and quick resource assignments. Calibration may be performed to account for differences in the frequency responses of transmit/receive chains at the access point and user terminals. The spatial processing may then be simplified by taking advantage of the reciprocal nature of the downlink and uplink and the calibration. | 11-20-2008 |
20080285670 | MIMO WLAN SYSTEM - A multiple-access MIMO WLAN system that employs MIMO, OFDM, and TDD. The system (1) uses a channel structure with a number of configurable transport channels, (2) supports multiple rates and transmission modes, which are configurable based on channel conditions and user terminal capabilities, (3) employs a pilot structure with several types of pilot (e.g., beacon, MIMO, steered reference, and carrier pilots) for different functions, (4) implements rate, timing, and power control loops for proper system operation, and (5) employs random access for system access by the user terminals, fast acknowledgment, and quick resource assignments. Calibration may be performed to account for differences in the frequency responses of transmit/receive chains at the access point and user terminals. The spatial processing may then be simplified by taking advantage of the reciprocal nature of the downlink and uplink and the calibration. | 11-20-2008 |
20080317158 | TIME-DOMAIN TRANSMIT AND RECEIVE PROCESSING WITH CHANNEL EIGEN-MODE DECOMPOSITION FOR MIMO SYSTEMS - Techniques for processing a data transmission at the transmitter and receiver. In an aspect, a time-domain implementation is provided which uses frequency-domain singular value decomposition and “water-pouring” results to derive time-domain pulse-shaping and beam-steering solutions at the transmitter and receiver. The singular value decomposition is performed at the transmitter to determine eigen-modes (i.e., spatial subchannels) of the MIMO channel and to derive a first set of steering vectors used to “precondition” modulation symbols. The singular value decomposition is also performed at the receiver to derive a second set of steering vectors used to precondition the received signals such that orthogonal symbol streams are recovered at the receiver, which can simplify the receiver processing. Water-pouring analysis is used to more optimally allocate the total available transmit power to the eigen-modes, which then determines the data rate and the coding and modulation scheme to be used for each eigen-mode. | 12-25-2008 |
20090092087 | MULTI-ANTENNA TRANSMISSION FOR SPATIAL DIVISION MULTIPLE ACCESS - An uplink channel response matrix is obtained for each terminal and decomposed to obtain a steering vector used by the terminal to transmit on the uplink. An “effective” uplink channel response vector is formed for each terminal based on its steering vector and its channel response matrix. Multiple sets of terminals are evaluated based on their effective channel response vectors to determine the best set (e.g., with highest overall throughput) for uplink transmission. Each selected terminal performs spatial processing on its data symbol stream with its steering vector and transmits its spatially processed data symbol stream to an access point. The multiple selected terminals simultaneously transmit their data symbol streams via their respective MIMO channels to the access point. The access point performs receiver spatial processing on its received symbol streams in accordance with a receiver spatial processing technique to recover the data symbol streams transmitted by the selected terminals. | 04-09-2009 |
20090322621 | ANTENNA ARRAY CONFIGURATIONS FOR HIGH THROUGHPUT MIMO WLAN SYSTEMS - The present disclosure provides techniques for configuring multi-element antenna arrays. Such antenna arrays may be designed with slot pairs separated by λ/2 along perpendicular axes (e.g., x and y-directions). One such array may have four or more co-located antenna element pairs formed with cross slots having the same rotational orientation. Another such array may have four or more co-located antenna element pairs formed with some cross slots having the same rotational orientation and other cross slots having a different rotational orientation. | 12-31-2009 |
20090323646 | METHOD AND APPARATUS FOR WIRLESS LAN (WLAN) DATA MULTIPLEXING - Embodiments addressing MAC processing for efficient use of high throughput systems are disclosed. Data associated with at least one MAC ID can be aggregated into a single byte stream. The single byte stream can be formatted into MAC PDUs and then muxed. The muxed MAC PDUs can then be transmitted on a single MAC frame. Muxing of the MAC PDUs can be based on the priority of the MAC PDUs or other criteria. A MAC header can comprise information about the muxed PDUs, such as a pointer, that identifies the location of the MAC PDUs within the MAC frame. A MAC frame can contain partial MAC PDUs. The transmitted muxed MAC PDUs can be retransmitted, and an acknowledgment or feedback scheme may be used to help manage the transmission of the protocol data units. | 12-31-2009 |
20090323851 | METHOD AND APPARATUS FOR UTILIZING CHANNEL STATE INFORMATION IN A WIRELESS COMMUNICATION SYSTEM - Techniques for transmitting data from a transmitter unit to a receiver unit in a multiple-input multiple-output (MIMO) communication system. In one method, at the receiver unit, a number of signals are received via a number of receive antennas, with the received signal from each receive antenna comprising a combination of one or more signals transmitted from the transmitter unit. The received signals are processed to derive channel state information (CSI) indicative of characteristics of a number of transmission channels used for data transmission. The CSI is transmitted back to the transmitter unit. At the transmitter unit, the CSI from the receiver unit is received and data for transmission to the receiver unit is processed based on the received CSI. | 12-31-2009 |
20100002570 | Transmit diversity and spatial spreading for an OFDM-based multi-antenna communication system - A multi-antenna transmitting entity transmits data to a single- or multi-antenna receiving entity using (1) a steered mode to direct the data transmission toward the receiving entity or (2) a pseudo-random transmit steering (PRTS) mode to randomize the effective channels observed by the data transmission across the subbands. The PRTS mode may be used to achieve transmit diversity or spatial spreading. For transmit diversity, the transmitting entity uses different pseudo-random steering vectors across the subbands but the same steering vector across a packet for each subband. The receiving entity does not need to have knowledge of the pseudo-random steering vectors or perform any special processing. For spatial spreading, the transmitting entity uses different pseudo-random steering vectors across the subbands and different steering vectors across the packet for each subband. Only the transmitting and receiving entities know the steering vectors used for data transmission. | 01-07-2010 |
20100020757 | RESOURCE ALLOCATION FOR MIMO-OFDM COMMUNICATION SYSTEMS - Techniques to schedule terminals for data transmission on the downlink and/or uplink in a MIMO-OFDM system based on the spatial and/or frequency “signatures” of the terminals. A scheduler forms one or more sets of terminals for possible (downlink or uplink) data transmission for each of a number of frequency bands. One or more sub-hypotheses may further be formed for each hypothesis, with each sub-hypothesis corresponding to (1) specific assignments of transmit antennas to the terminal(s) in the hypothesis (for the downlink) or (2) a specific order for processing the uplink data transmissions from the terminal(s) (for the uplink). The performance of each sub-hypothesis is then evaluated (e.g., based on one or more performance metrics). One sub-hypothesis is then selected for each frequency band based on the evaluated performance, and the one or more terminals in each selected sub-hypothesis are then scheduled for data transmission on the corresponding frequency band. | 01-28-2010 |
20100067401 | METHODS AND SYSTEMS FOR TRANSMISSION MODE SELECTION IN A MULTI CHANNEL COMMUNICATION SYSTEM - Techniques to select a suitable transmission mode for a data transmission in a multi channel communication system with multiple spatial channels having varying SNRs are presented in this disclosure. For certain embodiments, a closed-loop technique may be applied, in which back-off factors used to calculate an effective SNR value fed back to a transmitter are adjusted. An open-loop rate control scheme is also presented in which a transmitter may select a data rate and number of streams based on whether transmitted packets are received in error at a receiver. | 03-18-2010 |
20100074351 | METHOD AND APPARATUS FOR PROCESSING DATA FOR TRANSMISSION IN A MULTI-CHANNEL COMMUNICATION SYSTEM USING SELECTIVE CHANNEL INVERSION - Techniques to process data for transmission over a set of transmission channels selected from among all available transmission channels. In an aspect, the data processing includes coding data based on a common coding and modulation scheme to provide modulation symbols and pre-weighting the modulation symbols for each selected channel based on the channel's characteristics. The pre-weighting may be achieved by “inverting” the selected channels so that the received SNRs are approximately similar for all selected channels. With selective channel inversion, only channels having SNRs at or above a particular threshold are selected, “bad” channels are not used, and the total available transmit power is distributed across only “good” channels. Improved performance is achieved due to the combined benefits of using only the NS best channels and matching the received SNR of each selected channel to the SNR required by the selected coding and modulation scheme. | 03-25-2010 |
20100104039 | METHOD AND APPARATUS FOR PROCESSING DATA FOR TRANSMISSION IN A MULTI-CHANNEL COMMUNICATION SYSTEM USING SELECTIVE CHANNEL INVERSION - Techniques to process data for transmission over a set of transmission channels selected from among all available transmission channels. In an aspect, the data processing includes coding data based on a common coding and modulation scheme to provide modulation symbols and pre-weighting the modulation symbols for each selected channel based on the channel's characteristics. The pre-weighting may be achieved by “inverting” the selected channels so that the received SNRs are approximately similar for all selected channels. With selective channel inversion, only channels having SNRs at or above a particular threshold are selected, “bad” channels are not used, and the total available transmit power is distributed across only “good” channels. Improved performance is achieved due to the combined benefits of using only the NS best channels and matching the received SNR of each selected channel to the SNR required by the selected coding and modulation scheme. | 04-29-2010 |
20100208841 | TRANSMIT DIVERSITY PROCESSING FOR A MULTI-ANTENNA COMMUNICATION SYSTEM - For transmit diversity in a multi-antenna OFDM system, a transmitter encodes, interleaves, and symbol maps traffic data to obtain data symbols. The transmitter processes each pair of data symbols to obtain two pairs of transmit symbols for transmission from a pair of antennas either (1) in two OFDM symbol periods for space-time transmit diversity or (2) on two subbands for space-frequency transmit diversity. N | 08-19-2010 |
20100246704 | METHOD AND APPARATUS FOR PROCESSING DATA FOR TRANSMISSION IN A MULTI-CHANNEL COMMUNICATION SYSTEM USING SELECTIVE CHANNEL INVERSION - Techniques to process data for transmission over a set of transmission channels selected from among all available transmission channels. In an aspect, the data processing includes coding data based on a common coding and modulation scheme to provide modulation symbols and pre-weighting the modulation symbols for each selected channel based on the channel's characteristics. The pre-weighting may be achieved by “inverting” the selected channels so that the received SNRs are approximately similar for all selected channels. With selective channel inversion, only channels having SNRs at or above a particular threshold are selected, “bad” channels are not used, and the total available transmit power is distributed across only “good” channels. Improved performance is achieved due to the combined benefits of using only the NS best channels and matching the received SNR of each selected channel to the SNR required by the selected coding and modulation scheme. | 09-30-2010 |
20110028166 | METHOD AND SYSTEM FOR FEMTO CELL SELF-TIMING AND SELF-LOCATING - Devices and methods are provided for providing self-timing and self-locating in an access point (AP) base station. In one embodiment, the method involves receiving Satellite Positioning System (SPS) signals from a first data source (e.g., plurality of satellites), wherein the SPS signals may include SPS time data, SPS frequency data, and SPS position data. The method may further involve obtaining from a second data source (e.g., cell site, terrestrial navigation station, server, user input interface, etc.) at least one of second time data, second frequency data and second position data, and determining relative reliability of the first and second data sources. | 02-03-2011 |
20110055326 | METHODS AND SYSTEMS FOR SERVICE DISCOVERY MANAGEMENT IN PEER-TO-PEER NETWORKS - Certain embodiments of the present disclosure relate to a method and an apparatus for managing and optimizing service discovery in a peer-to-peer (P2P) wireless network. Nodes of the P2P network advertise their capabilities to their peers in the form of services. Efficient propagation and management of node's services to other nodes is proposed in the present disclosure. | 03-03-2011 |
20110103523 | SINGLE-BURST ACQUISITION FOR WIRELESS COMMUNICATION SYSTEM - Techniques for performing acquisition of packets are described. First detection values may be determined based on a first plurality of samples, e.g., by performing delay-multiply-integrate on the samples. Power values may be determined based on the first plurality of samples, e.g., by performing multiply-integrate on the samples. The first detection values may be averaged to obtain average detection values. The power values may also be averaged to obtain average power values. Whether a packet is presence may be determined based on the average detection values and the average power values. Second detection values may be determined based on a second plurality of samples. The start or the packet may be determined based on the first and second detection values. A third detection value may be determined based on a third plurality of samples. Frequency error of the packet may be estimated based on the first and third detection values. | 05-05-2011 |
20110142097 | DATA TRANSMISSION WITH SPATIAL SPREADING IN A MIMO COMMUNICATION SYSTEM - For data transmission with spatial spreading, a transmitting entity (1) encodes and modulates each data packet to obtain a corresponding data symbol block, (2) multiplexes data symbol blocks onto NS data symbol streams for transmission on NS transmission channels of a MIMO channel, (3) spatially spreads the NS data symbol streams with steering matrices, and (4) spatially processes NS spread symbol streams for full-CSI transmission on NS eigenmodes or partial-CSI transmission on NS spatial channels of the MIMO channel. A receiving entity (1) obtains NR received symbol streams via NR receive antennas, (2) performs receiver spatial processing for full-CSI or partial-CSI transmission to obtain NS detected symbol streams, (3) spatially despreads the NS detected symbol streams with the same steering matrices used by the transmitting entity to obtain NS recovered symbol streams, and (4) demodulates and decodes each recovered symbol block to obtain a corresponding decoded data packet. | 06-16-2011 |
20110235744 | PILOTS FOR MIMO COMMUNICATION SYSTEMS - Pilots suitable for use in MIMO systems and capable of supporting various functions are described. The various types of pilot include—a beacon pilot, a MIMO pilot, a steered reference or steered pilot, and a carrier pilot. The beacon pilot is transmitted from all transmit antennas and may be used for timing and frequency acquisition. The MIMO pilot is transmitted from all transmit antennas but is covered with different orthogonal codes assigned to the transmit antennas. The MIMO pilot may be used for channel estimation. The steered reference is transmitted on specific eigenmodes of a MIMO channel and is user terminal specific. The steered reference may be used for channel estimation. The carrier pilot may be transmitted on designated subbands/antennas and may be used for phase tracking of a carrier signal. Various pilot transmission schemes may be devised based on different combinations of these various types of pilot. | 09-29-2011 |
20110317671 | MULTIPLE-ACCESS HYBRID OFDM-CDMA SYSTEM - In one aspect of a multiple-access OFDM-CDMA system, data spreading is performed in the frequency domain by spreading each data stream with a respective spreading code selected from a set of available spreading codes. To support multiple access, system resources may be allocated and de-allocated to users (e.g., spreading codes may be assigned to users as needed, and transmit power may be allocated to users). Variable rate data for each user may be supported via a combination of spreading adjustment and transmit power scaling. Interference control techniques are also provided to improve system performance via power control of the downlink and/or uplink transmissions to achieve the desired level of performance while minimizing interference. A pilot may be transmitted by each transmitter unit to assist the receiver units perform acquisition, timing synchronization, carrier recovery, handoff, channel estimation, coherent data demodulation, and so on. | 12-29-2011 |
20120127899 | METHOD AND SYSTEM FOR PROVIDING BEAMFORMING FEEDBACK IN WIRELESS COMMUNICATION SYSTEMS - Techniques to support beamforming for stations in a wireless network are described. A station may support beamforming with implicit or explicit feedback by having capabilities to transmit and receive sounding frames, responding to training request by sending a sounding frame, and responding to request for explicit feedback. In one explicit beamforming embodiment, the station may send a first frame with an explicit feedback request and may also send a Null Data Packet (NDP) having at least one training field but no data field. The station may receive a second frame with explicit feedback, which may be derived based on the NDP. The station may derive steering information based on explicit feedback and may then send a steered frame with beamforming based on the steering information. Other aspects, embodiments, and features are also claimed and described. | 05-24-2012 |
20120140664 | RANDOM ACCESS FOR WIRELESS MULTIPLE-ACCESS COMMUNICATION SYSTEMS - Techniques for facilitating random access in wireless multiple-access communication systems are described. A random access channel (RACH) is defined to comprise a “fast” RACH (F-RACH) and a “slow” RACH (S-RACH). The F-RACH and S-RACH can efficiently support user terminals in different operating states and employ different designs. The F-RACH can be used to quickly access the system, and the S-RACH is more robust and can support user terminals in various operating states and conditions. The F-RACH may be used by user terminals that have registered with the system and can compensate for their round trip delays (RTDs) by properly advancing their transmit timing. The S-RACH may be used by user terminals that may or may not have registered with the system, and may or may not be able to compensate for their RTDs. Other aspects, embodiments, and features are also claimed and described. | 06-07-2012 |
20120213181 | TRANSMIT DIVERSITY AND SPATIAL SPREADING FOR AN OFDM-BASED MULTI-ANTENNA COMMUNICATION SYSTEM - A multi-antenna transmitting entity transmits data to a single- or multi-antenna receiving entity using (1) a steered mode to direct the data transmission toward the receiving entity or (2) a pseudo-random transmit steering (PRTS) mode to randomize the effective channels observed by the data transmission across the subbands. For transmit diversity, the transmitting entity uses different pseudo-random steering vectors across the subbands but the same steering vector across a packet for each subband. The receiving entity does not need to have knowledge of the pseudo-random steering vectors or perform any special processing. For spatial spreading, the transmitting entity uses different pseudo-random steering vectors across the subbands and different steering vectors across the packet for each subband. Only the transmitting and receiving entities know the steering vectors used for data transmission. Other aspects, embodiments, and features are also claimed and disclosed. | 08-23-2012 |
20120213302 | MULTI-ANTENNA TRANSMISSION FOR SPATIAL DIVISION MULTIPLE ACCESS - An uplink channel response matrix is obtained for each terminal and decomposed to obtain a steering vector used by the terminal to transmit on the uplink. An “effective” uplink channel response vector is formed for each terminal based on its steering vector and its channel response matrix. Multiple sets of terminals are evaluated based on their effective channel response vectors to determine the best set (e.g., with highest overall throughput) for uplink transmission. Each selected terminal performs spatial processing on its data symbol stream with its steering vector and transmits its spatially processed data symbol stream to an access point. The multiple selected terminals simultaneously transmit their data symbol streams via their respective MIMO channels to the access point. The access point performs receiver spatial processing on its received symbol streams in accordance with a receiver spatial processing technique to recover the data symbol streams transmitted by the selected terminals. | 08-23-2012 |
20120250788 | SPATIAL SPREADING IN A MULTI-ANTENNA COMMUNICATION SYSTEM - Spatial spreading is performed in a multi-antenna system to randomize an “effective” channel observed by a receiving entity for each transmitted data symbol block. For a MIMO system, at a transmitting entity, data is processed (e.g., encoded, interleaved, and modulated) to obtain N | 10-04-2012 |
20130182598 | METHODS AND SYSTEMS FOR TRANSMISSION MODE SELECTION IN A MULTI CHANNEL COMMUNICATION SYSTEM - Techniques to select a suitable transmission mode for a data transmission in a multi channel communication system with multiple spatial channels having varying SNRs are presented in this disclosure. For certain embodiments, a closed-loop technique may be applied, in which back-off factors used to calculate an effective SNR value fed back to a transmitter are adjusted. An open-loop rate control scheme is also presented in which a transmitter may select a data rate and number of streams based on whether transmitted packets are received in error at a receiver. | 07-18-2013 |
20130188677 | REDUCED COMPLEXITY BEAM-STEERED MIMO OFDM SYSTEM - Techniques for transmitting data using channel information for a subset of all subcarriers used for data transmission are described. A transmitter station receives channel information for at least one subcarrier that is a subset of multiple subcarriers used for data transmission. The channel information may include at least one transmit steering matrix, at least one set of eigenvectors, at least one channel response matrix, at least one channel covariance matrix, an unsteered pilot, or a steered pilot for the at least one subcarrier. The transmitter station obtains at least one transmit steering matrix for the at least one subcarrier from the channel information and determines a transmit steering matrix for each of the multiple subcarriers. The transmitter station performs transmit steering or beam-steering for each of the multiple subcarriers with the transmit steering matrix for that subcarrier. | 07-25-2013 |
20130235825 | MIMO SYSTEM WITH MULTIPLE SPATIAL MULTIPLEXING MODES - A MIMO system supports multiple spatial multiplexing modes for improved performance and greater flexibility. These modes may include (1) a single-user steered mode that transmits multiple data streams on orthogonal spatial channels to a single receiver, (2) a single-user non-steered mode that transmits multiple data streams from multiple antennas to a single receiver without spatial processing at a transmitter, (3) a multi-user steered mode that transmits multiple data streams simultaneously to multiple receivers with spatial processing at a transmitter, and (4) a multi-user non-steered mode that transmits multiple data streams from multiple antennas (co-located or non co-located) without spatial processing at the transmitter(s) to receiver(s) having multiple antennas. For each set of user terminal(s) selected for data transmission on the downlink and/or uplink, a spatial multiplexing mode is selected for the user terminal set from among the multiple spatial multiplexing modes supported by the system. | 09-12-2013 |
20130279614 | OFDM COMMUNICATION SYSTEM WITH MULTIPLE OFDM SYMBOL SIZES - Techniques to use OFDM symbols of different sizes to achieve greater efficiency for OFDM systems. The system traffic may be arranged into different categories (e.g., control data, user data, and pilot data). For each category, one or more OFDM symbols of the proper sizes may be selected for use based on the expected payload size for the traffic in that category. For example, control data may be transmitted using OFDM symbols of a first size, user data may be transmitted using OFDM symbols of the first size and a second size, and pilot data may be transmitted using OFDM symbols of a third size or the first size. In one exemplary design, a small OFDM symbol is utilized for pilot and for transport channels used to send control data, and a large OFDM symbol and the small OFDM symbol are utilized for transport channels used to send user data. | 10-24-2013 |
20130281086 | METHODS AND SYSTEMS FOR SERVICE DISCOVERY MANAGEMENT IN PEER-TO-PEER NETWORKS - Certain embodiments of the present disclosure relate to a method and an apparatus for managing and optimizing service discovery in a peer-to-peer (P2P) wireless network. Nodes of the P2P network advertise their capabilities to their peers in the form of services. Efficient propagation and management of node's services to other nodes is proposed in the present disclosure. | 10-24-2013 |
20130281146 | METHODS AND SYSTEMS FOR PEER-TO-PEER NETWORK DISCOVERY USING MULTI-USER DIVERSITY - Certain embodiments of the present disclosure relate to a method for improving the effective coverage of nodes within a peer-to-peer (P2P) wireless network. Collection of nodes of the P2P network can have a larger aggregate coverage footprint than any given single node. This inherent multi-site property of P2P wireless networks can be exploited to provide each node with benefits of multi-user diversity, thus improving discovery of devices in the P2P network. | 10-24-2013 |
20140348258 | MIMO WLAN SYSTEM - A multiple-access MIMO WLAN system that employs MIMO, OFDM, and TDD. The system (1) uses a channel structure with a number of configurable transport channels, (2) supports multiple rates and transmission modes, which are configurable based on channel conditions and user terminal capabilities, (3) employs a pilot structure with several types of pilot (e.g., beacon, MIMO, steered reference, and carrier pilots) for different functions, (4) implements rate, timing, and power control loops for proper system operation, and (5) employs random access for system access by the user terminals, fast acknowledgment, and quick resource assignments. Calibration may be performed to account for differences in the frequency responses of transmit/receive chains at the access point and user terminals. The spatial processing may then be simplified by taking advantage of the reciprocal nature of the downlink and uplink and the calibration. | 11-27-2014 |
20150085703 | METHODS AND SYSTEMS FOR EXPLOITATION OF WELL-CONNECTED NODES IN PEER-TO-PEER WIRELESS NETWORKS - Certain embodiments of the present disclosure relate to a method for increasing a capacity in a peer-to-peer (P2P) wireless network. A scheme has been proposed in which well-connected nodes of the P2P wireless network can be exploited in a manner that increases the overall connectivity of all the nodes in the network. | 03-26-2015 |
20150085751 | METHODS AND SYSTEMS FOR EXPLOITATION OF WELL-CONNECTED NODES IN PEER-TO-PEER WIRELESS NETWORKS - Certain embodiments of the present disclosure relate to a method for increasing a capacity in a peer-to-peer (P2P) wireless network. A scheme has been proposed in which well-connected nodes of the P2P wireless network can be exploited in a manner that increases the overall connectivity of all the nodes in the network. | 03-26-2015 |