Patent application number | Description | Published |
20090296684 | Packet synchronizing for communications over a wireless communication system - Synchronization methods and systems for communications over a multi-band system are presented. A synchronization technique for communications over a multi-band system includes receiving a packet of preamble symbols respectively transmitted over a sequence of frequency sub-bands according to one of a plurality of frequency hopping patterns, wherein the plurality of frequency hopping patterns are partitioned into a plurality of disjoint groups, each group having a different associated periodicity; computing, in parallel, respective autocorrelation values of the packet received in a selected frequency sub-band at a plurality of symbol delays; and selecting one of the plurality of groups of frequency hopping patterns based on the autocorrelation values at the plurality of symbol delays. | 12-03-2009 |
20100165916 | Wireless Star Network with Standby Central Node - A wireless network with a star topology includes a first central node, a second central node, wherein the first and second nodes are functionally equivalent. A set of leaf nodes are configured to communicate with either the first central node or the second central node via wireless links, depending whether the central nodes are active or inactive. | 07-01-2010 |
20100246635 | Methods and apparatus for narrow band interference detection and suppression in ultra-wideband systems - An exemplary method is disclosed to accurately estimate the center frequency of a narrow-band interference (NBI). The exemplary method uses multi-stage autocorrelation-function (ACF) to estimate an NBI frequency. The exemplary method allows an accurate estimation of the center frequency of NBI in an Ultra-Wideband system. A narrow band interference (NBI) estimator based on such a method allows a low complexity hardware implementation. The exemplary method estimates the frequency in multiple stages. Each stage performs an ACF operation on the received signals. The first stage gives an initial estimation and the following stages refine the estimation. The results of all stages are combined to produce the final estimation. An apparatus based on such a multi-stage narrow band interference frequency detector is also disclosed to improve the accuracy by combining various filters with the detector. | 09-30-2010 |
20110194452 | Transmitting Data with Multiple Priorities as OFDM Symbols - A transmitter transmits data having a set of two or more priorities on subcarriers using orthogonal frequency division multiplexing (OFDM) symbols. The transmitter includes a media access (MAC) layer, wherein the MAC layer further includes a queue for storing data at each priority, a rate control block connected to each queue, and a physical (PHY) layer. The PHY layer further includes a channel coder for each priority, wherein each channel coder is connected to the corresponding queue to receive data, and to the rate control block to send coding information. | 08-11-2011 |
20120002599 | Implicit Channel Sounding for Closed-Loop Transmission in MIMO-OFDM Wireless Networks - Symbols are encoded in a transmitter of a wireless network that uses multiple-input and multiple-output (MIMO) orthogonal frequency division multiplexing (MIMO-OFDM) by partitioning the sub-carriers to be used for transmitting the symbol into a set of K groups of contiguous sub-carriers. For each group k of N | 01-05-2012 |
20120163486 | Method of Selecting Antennas in a Wireless Communicating Network for High Reliability and Low Latency - A network includes a transmitter and a receiver, wherein the transmitter includes a set of transmit antennas and the receiver includes a set of receive antennas. The transmitter duplicates a packet as copies of the packet, and selects subsets of the set of transmit antennas independent of channel characteristics between the subsets of transmit antennas and the set of receive antennas, wherein combinations of the antennas in the subsets of the transmit antennas are different. The receiver selects subsets of the set of receive antennas independent of channel characteristics between the subsets of receive antennas and the set of transmit antennas, wherein combinations of the antennas in the subsets of the receive antennas are different. The selected subsets are used to transmit the packet, and retransmit the packet in case of a failure in a previous transmission. | 06-28-2012 |
20120168523 | Method for Physically Making Objects Continuous Functions - A set of symbols is encoded using a continuous mapping function to produce corresponding encoded functions, wherein the mapping function is continuous and values of the encoded functions are real and vary continuously. The encoded functions are summed in a spatial domain to generate a summed function, which is biased so that values of a biased function are all positive and real. Then, a physical property of the object is altered according the biased function to arrange a mark on the object. | 07-05-2012 |
20120185755 | METHOD FOR PERFORMING SOFT DECISION DECODING OF EUCLIDEAN SPACE REED-MULLER CODES - Soft decision decoding of a codeword of a Reed-Muller (RM) code by | 07-19-2012 |
20120327792 | Method for Discovering and Maintaining Routes in Smart Meter Networks - A set of routes are discovered in a network including concentrators, smart meters and an imaginary node. Each concentrator node, a source, broadcasts a route request (RREQ) packet to the imaginary destination node. Intermediate nodes store a route as a node list (NL) in the RREQ packet and as a route table (RT) in the node. Then, each smart meter node can select a primary route and a secondary route from the smart meter node to any concentrator from the route table. | 12-27-2012 |
20130114765 | Method for Reducing Interference in OFDM Wireless Networks - Interference in a received orthogonal frequency division multiplexing (OFDM) symbol, modulated according to selected constellation points S | 05-09-2013 |
20130176174 | Method and System for Estimating Time of Arrival of Signals Using Maximum Eigenvalue Detection - A method estimates the time-of-arrival (ToA) of signals received via multipath channels. The received signal of a number of trials is first passed through a band-pass filter and then sampled. The presence of a channel tap within a time window is estimated by comparing a threshold to a largest eigenvalue of the covariance matrix of a time window. The signal samples are used to calculated a band region of a complete covariance matrix. After the band region has been updated for all signal samples, the covariance matrices for a moving window can be extracted from the band region. The ToA is estimated as the ending time of the leading window, which is the earliest window, such that the largest eigenvalue is larger than a given threshold. | 07-11-2013 |
20130208583 | Avoiding Broken Links in Smart Meter Networks for Loop-Free Routing of Packets - Broken links in a sensor network are avoided by representing the network as a DODAG. A rank associated with each node defines a position of each node relative to other nodes, and the rank is in a form of a proper fraction, and the rank of each node never increases to enable loop-free routing. | 08-15-2013 |
20130223334 | Channel Scan for Smart Meter Networks to Determine Operating Channels - An operation channel in a multi-hop network is determined. The network uses a set of channels, and one of the nodes is a network management node. The operation channel is selected in the network management node. Then, the network management node broadcasts a channel information packet including the operation channel using all channels. The channel information packet is received in each of other nodes, either directly from the network management node or from an intermediate node that received and rebroadcasted the channel information packet. Lastly, the operation channel in each node is set according to the channel information packet until the network is formed. | 08-29-2013 |
20130259014 | Location Based Data Delivery Schedulers - Packets are transmitted by a server to mobile nodes in a coverage area of a wireless network using a coverage and reliability map, which indicates qualities and reliabilities of links between the server and the nodes. When a new packet is received in the server, the server transmits the packet if a current load of the packets including the new packet is less than a peak load constraint. Otherwise, the new packet is delayed for one time slot. | 10-03-2013 |
20130262648 | Location Based Data Delivery Schedulers - Packets are transmitted by a server to mobile nodes in a coverage area of a wireless network using a coverage and reliability map, which indicates qualities and reliabilities of links between the server and the nodes. When a new packet is received in the server, the server transmits the packet if a current load of the packets including the new packet is less than a peak load constraint. Otherwise, the new packet is delayed for one time slot. Packets are transmitted according to associated priorities. | 10-03-2013 |
20130308700 | Method and System for Communicating Multimedia Using Reconfigurable Rateless Codes and Decoding In-Process Status Feedback - A method and system use capacity-approaching rateless code to communicate multimedia data even with very short codewords, such as 64 bits or less, via erasure and noise channels. The method provides a way to design the edge degree distribution of rateless codes for any arbitrary channel. Based on an equivalent metric of decoding behavior in any channels, the degree distribution of a rateless code such as Luby-transform codes and raptor codes is optimized based on in-process status of decoding. A regularized least-squares optimization is used to avoid erroneous decoding. Multiple feedbacks can further improve the performance. | 11-21-2013 |
20140133535 | Signal Classification for Adaptive Signal Detection - Signal received in a wireless network are detected by arranging samples of the signal in a set of windows. For each window, estimating interference, an average signal, noise and interference ratio (SINR), and a channel. For each window, also classifying a type of a process of a set of processes of a receiver. Then, selecting the process for each windows according to the type to detect the signal in the window. | 05-15-2014 |
20140204759 | Load Balanced Routing for Low Power and Lossy Networks - A node includes a receiver for receiving a first packet from a first node at a first time and a second packet from a second node at a second time, a processor for determining the first time and the second time and for comparing the first time with the second time to produce a ratio of workloads of the first node and the second node, and a transmitter for transmitting packets to the first and the second nodes based on the ratio. | 07-24-2014 |
20140241471 | Method and System for Communicating Data Wirelessly Using Probabilistic Data Association - A signal received via a fading channel is decoded in radio frequency receiver by first demodulating the signal to a baseband signal, and serial to parallel converting the baseband signal to a precoded signal. Then, a channel matrix is estimated from the precoded signal, and symbols are detected in the precoded signal using the channel matrix. The decoding uses probabilistic data association. The detecting initializes a probability distribution for each symbol, and selects an ordering in which to update the probability distributions. The probability distribution for each symbol are updated according to the ordering, until a termination condition is reached, and then demapped and parallel to serial converted to estimate a sequence of bits used to generate the signal. | 08-28-2014 |
20140292581 | Method and System for Determining Locations of Smartkeys - A location of a smartkey is determined by first determining coordinates of a set of candidate vertices of an array of receive antennas at a receiver based on maximal magnetic field voltages in the receive antennas due transmitting a radio signal (RF) by the smartkey. A set of candidate locations of the transmitter is determined based on the coordinate of the set of vertices. A set of final candidate locations is determined based on a predetermined threshold of the voltages. The final candidate locations are then combined to determine the location of the smartkey. | 10-02-2014 |
20140304383 | Method for Clustering Devices in Machine-to-Machine Networks to Minimize Collisions - Nodes in a network are clustered by first determining, in each node, a cluster head capability (CHC). The CHC is broadcasting, directly or indirectly, until all nodes have received the CHCs. Each node nominates, one or more candidate cluster heads based on the CHCs, and then, in each node, at least one cluster head is selected from the candidate cluster head nodes based on maximal CHCs. | 10-09-2014 |
20150049731 | Method for Coding OFDMA Data without Pilot Symbols - A wireless network includes a set of nodes. Each node includes a transmitter and a receiver. A block of data bits is converted to a block of data symbols. The block of data symbols is partitioning timewise into groups of data symbols. A set of subcarriers is assigned to each group of data symbols, and each group of data symbols is spread to a chip sequence using a coding block of spreading sequences, wherein the spreading sequences are based on types of the groups of data symbols. Then, after the spreading, the chips are transmitted as orthogonal frequency-division multiplexing (OFDM) data symbols on the assigned subcarriers. | 02-19-2015 |
20150085668 | Discovering Stable Routes in Wireless Networks - A method discovers routes for forwarding packets from source nodes (sources) to sink nodes (sinks) in a wireless network, wherein some neighboring sources act as relay nodes. Each source measures a rate of receiving control messages from each neighboring node. Then, the data packets are forwarded from a particular source to the sink via the neighboring nodes having a lowest rate. | 03-26-2015 |
20150085696 | Method for Discovering Neighboring Nodes in Wireless Networks - A method discovers neighboring nodes in a wireless network of nodes. The nodes include a set of concentrators acting as IPv6 routers and a set of sensor nodes acting as IPv6 hosts. The sensor nodes can also act as relay nodes. In each node, a 64-bit interface ID is configured using a 48-bit MAC address. In each node, a unique IPv6 link-local address is configured using the 64-bit interface ID. In each node, the neighboring nodes are discovered by transmitting unsolicited Neighbor Advertisement (NA) messages. A Router Advertisement (RA) messages is distributed from the concentrators to the sensor nodes meters by using the relay nodes. In each node, a unique IPv6 address is configured and registered at the concentrators by using the relay nodes. | 03-26-2015 |