Patent application number | Description | Published |
20100046666 | SIGNAL PROCESSING WITH CHANNEL EIGENMODE DECOMPOSITION AND CHANNEL INVERSION FOR MIMO SYSTEMS - Techniques for processing a data transmission at a transmitter and receiver, which use channel eigen-decomposition, channel inversion, and (optionally) “water-pouring”. At the transmitter, (1) channel eigen-decomposition is performed to determine eigenmodes of a MIMO channel and to derive a first set of steering vectors, (2) channel inversion is performed to derive weights (e.g., one set for each eigenmode) used to minimize ISI distortion, and (3) water-pouring may be performed to derive scaling values indicative of the transmit powers allocated to the eigenmodes. The first set of steering vectors, weights, and scaling values are used to derive a pulse-shaping matrix, which is used to precondition modulation symbols prior to transmission. At the receiver, channel eigen-decomposition is performed to derive a second set of steering vectors, which are used to derive a pulse-shaping matrix used to condition received symbols such that orthogonal symbol streams are recovered. | 02-25-2010 |
20100169396 | EFFICIENT COMPUTATION FOR EIGENVALUE DECOMPOSITION AND SINGULAR VALUE DECOMPOSITION OF MATRICES - For eigenvalue decomposition, a first set of at least one variable is derived based on a first matrix being decomposed and using Coordinate Rotational Digital Computer (CORDIC) computation. A second set of at least one variable is derived based on the first matrix and using a look-up table. A second matrix of eigenvectors of the first matrix is then derived based on the first and second variable sets. To derive the first variable set, CORDIC computation is performed on an element of the first matrix to determine the magnitude and phase of this element, and CORDIC computation is performed on the phase to determine the sine and cosine of this element. To derive the second variable set, intermediate quantities are derived based on the first matrix and used to access the look-up table. | 07-01-2010 |
20100215115 | RECEIVER SPATIAL PROCESSING FOR EIGENMODE TRANSMISSION IN A MIMO SYSTEM - For eigenmode transmission with minimum mean square error (MMSE) receiver spatial processing, a transmitter performs spatial processing on NS data symbol streams with steering vectors to transmit the streams on NS spatial channels of a MIMO channel. The steering vectors are estimates of transmitter steering vectors required to orthogonalize the spatial channels. A receiver derives a spatial filter based on an MMSE criterion and with an estimate of the MIMO channel response and the steering vectors. The receiver (1) obtains NR received symbol streams from NR receive antennas, (2) performs spatial processing on the received symbol streams with the spatial filter to obtain NS filtered symbol streams, (3) performs signal scaling on the filtered symbol streams with a scaling matrix to obtain NS recovered symbol streams, and (4) processes the NS recovered symbol streams to obtain NS decoded data streams for the NS data streams sent by the transmitter. | 08-26-2010 |
20100246642 | MULTI-ACCESS HYBRID OFDM-CDMA SYSTEM - In one aspect of a multiple-access OFDM-CDMA system, the 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. | 09-30-2010 |
20100296407 | 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. | 11-25-2010 |
20110080869 | 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. | 04-07-2011 |
20110081908 | METHODS AND SYSTEMS FOR REGISTRATIONS AND SERVICE ANNOUNCEMENTS IN PEER-TO-PEER NETWORKS VIA CELLULAR OVERLAYS - Certain embodiments of the present disclosure relate to a method and an apparatus for registration and service announcements in peer-to-peer wireless networks to increase capacity of such networks. The present disclosure proposes a hybrid registration mechanism allowing a peer-to-peer node to leverage an administrative architecture of a neighboring cellular system. | 04-07-2011 |
20110106837 | 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. | 05-05-2011 |
20120033585 | 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. | 02-09-2012 |