Abstract: 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.

Abstract: An encoder in a transmitter uses space-time trellis coding. An input bitstream is multiplexed to produce in parallel a set of output bitstreams. A multiplier applies a code generating weight to each output bitstream, which are combined, mapped and transmitted by a single antenna.

Abstract: A computer implemented method selects antennas in a multiple-input, multiple-output wireless local area network that includes multiple stations, and each station includes a set of antennas. Multiple consecutively transmitted sounding packets are received in a station. Each sounding packet corresponds to a different subset of the set of antennas. A channel matrix is estimated from the multiple consecutively transmitted sounding packets, and a subset of antennas is selected according to the channel matrix.

Abstract: 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.

Abstract: 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.

Abstract: Embodiments of the invention describe a method for antenna selection (AS) in a wireless communication network, the network comprising user equipment (UE), configured to transmit a sounding reference signal (SRS) from a subset of antennas at a time without transmitting user data. The method transmits a first SRS from a first subset of antennas in a first subframe, wherein the first subframe does not include the user data, and transmits a second SRS from a second subset of antennas in a second subframe, wherein the second subframe does not include the user data. After receiving, in response to the transmitting the first SRS and the second SRS, information identifying an optimal subset of antennas from the first subset of antennas and the second subset of antennas, the method selects the optimal set of antennas such that the optimal subset of antennas is selected without transmitting the user data.

Abstract: A method allocates bandwidth to channels in an orthogonal frequency division multiple access and time division multiple access (TDMA) network. The network includes a master device (master) communicating with a set of slave devices (slaves). The master defines a set ?m of logical indices ? of a set of N physical subcarriers for a set of M data streams to be allocated to a set of Nd logical data subcarriers according to ?m={?|?=iM+m, i=0,1,2, . . . , d?1}, where d=Nd/M. The set of N data subcarriers is mapped to the set of Nd logical subcarriers according to the logical indices, and the data subcarriers are allocated to the logical subcarriers.

Abstract: A method estimates a wireless channel at a receiver. The signal is transmitted using narrowband orthogonal frequency division demultiplexing (OFDM) and frequency subcarriers, and the signal includes a set of data tones and a set of pilot tones. The channel and pilot tone interference are estimated based on all the pilot tones extracted from the signal and a channel model. The set of data are equalized based on the channel estimate. Data interference is detected according to the pilot interference and the equalized data tones. Subcarrier interference-to-noise ratios are determined based on the data interference. Signal strengths of the data tones are determined based on the equalized data tones, log-likelihood ratios of bits represented by the data tones are determined based on the subcarrier interference-to-noise ratios and the signal strength of the data tones.

Abstract: The embodiments of the invention describe method and system for maximizing capacity of a distributed antenna system. A relaying antenna is selected to maximize a signal-to-leakage ratio (SLR) ratio of the distributed antenna system. Further, the capacity of the system is improved by allocating a signal power based on a pseudo-capacity criterion such that an average pseudo capacity of the distributed antenna system is maximized.

Abstract: In a network for a safety system in a transportation system, the transportation system includes a shaft and a car arranged in the shaft. A first wall node is at a first end of the shaft and a second wall node is at a second end of the shaft to communicate safety messages with the car. Each wall node includes at least one wireless transceiver connected to one or more antennas. Each car in the shaft includes at least two wireless transceiver connected to one or more antennas, wherein the first transceiver of the car uses a first frequency and the second transceiver of the car uses a second frequency to communicate each safety messages in duplicate. A wired backbone connects the set of wall nodes to a controller of the safety system of the transportation system.

Abstract: Symbols in information are encoded as a codeword using a differential orthogonal code. The codeword is stored in a substrate. A moving sensor acquires an image of the codeword in the substrate and decodes the codeword using a balanced differential decoder. The codeword can be painted as lane markings on a road surface.

Abstract: A computer implemented method selects antennas in a multiple-input, multiple-output wireless local area network that includes multiple stations, and each station includes a set of antennas. Multiple consecutively transmitted sounding packets are received in a station. Each sounding packet corresponds to a different subset of the set of antennas. A channel matrix is estimated from the multiple consecutively transmitted sounding packets. A frame including a high throughput (HT) control field is sent to initiate a selecting of antennas, and a subset of antennas is selected according to the channel matrix.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Embodiments of the invention describe a method for antenna selection (AS) in a wireless communication network, the network comprising user equipment (UE), wherein the UE comprises a plurality of subsets of antennas including a first subset of antennas and a second subset of antennas, and wherein the UE is configured to transmit a sounding reference signal (SRS) from a subset of antennas at a time. The method transmits a first SRS from the first subset of antennas, transmits a second SRS from the second subset of antennas, receives, in response to the transmitting the first SRS and the second SRS, information identifying an optimal subset of antennas from the first subset of antennas and the second subset of antennas, and transmits user data from the optimal subset of antennas.

Abstract: In an orthogonal frequency division multiplexing (OFDM) network, a set of pseudo random sequences (PRS) are stored at a transmitter and a receiver. Each OFDM symbol is mapped to subcarriers for a set of transmit antennas to produce a mapped symbol. The mapped symbol is encoded using a pseudo-random phase precoder (PRPP) and the PRS to produce a precoded symbol. An inverse fast Fourier transform (IFFT) is applied to the precoded symbol, and the encoded symbol is transmitted to the receiver using the set of transmit antennas.

Abstract: A method selects antennas in a multiple-input, multiple-output (MIMO) wireless local area network (WLAN) that includes a plurality of stations, and each station includes a set of antennas. Plural consecutive packets, received at a station, include plural consecutive sounding packets. Each sounding packet corresponds to a different subset of the set of antennas, and at least one of the plural consecutive packets includes a high throughput (HT) control field including a signal to initiate antenna selection and a number N indicative of a number of sounding packets which follow the at least one packet including the HT control field and which are to be used for antenna selection. A channel matrix is estimated based on a characteristic of the channel as indicated by the received N sounding packets, and a subset of antennas is selected according to the channel matrix. Station and computer program product embodiments include similar features.

Abstract: A base station transmits a set of sounding requests to a set of mobile station (MS) in a cell, using a set of beams, wherein there is one beam for each sounding request. Qualities of sounding signals transmitted by the set of MSs in response to receiving the sounding request are measured, and the set of MSs are grouped into subsets according to the qualities, wherein there is one subset of MSs associated with each beam.

Abstract: The invention provides a data structure embodied in a computer readable media. The data structure is a protocol data packet (PDU) communicated in a mobile multihop network between stations. The data structure includes a relay media access header, a payload and an optional cyclical redundancy checksum for the protocol data unit, and an indication whether the PDU is a relay media access protocol data unit or not.