Abstract: A method, system, and computer program product for wireless communication between an initiator station and a responder station. The method includes assigning a transmit window having a predefined window duration to the initiator; sending a request-to send signal (S41) from the initiator to the responder; sending a clear-to-send (S42) signal and a request for reverse transmission from the responder to the initiator; sending forward data and a reverse transmission permission indicator from the initiator to the responder, and sending reverse data from the responder to the initiator within the transmit window assigned to the initiator.

Abstract: A method selects antennas in an OFDMA network. A channel state of a downlink is measured using a downlink subframe received in a mobile station from a base station. A channel state of an uplink is measured using an uplink subframe received in the base station from the mobile station. Next, the method compares the channel states to determine whether the downlink and the uplink are reciprocal or not. The mobile station can perform receive antenna selection based on the quality of the downlink channel state. The mobile station can also perform transmit antenna selection when instructed by the base station.

Abstract: 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.

Abstract: A wireless network includes a base station (BS), a set of mobile stations (MS), and a set of repeaters. The channels between the BS and the repeater and between the repeater and the MS include a downlink (DL) and an uplink (UL). A BS specifies a first center frequency F2 for the channel between the BS and MS, and a second center frequency F1 for the channel between the repeater and the MS. The first center frequency F2 and the second center frequency are transmitted to the repeater and the MS in channel descriptor messages.

Abstract: A method signals a quality of range estimates in a UWB network. For each range estimate, a confidence level of a range estimate is signaled, a confidence interval for the range estimate is signaled, and a confidence interval scaling factor for the confidence interval is signaled.

Abstract: A method transmits an L bit packet in a relay network including a source node, a relay node and a destination node. The source node partitions the packet into first fragment of ?L bits and a second fragment of (1??) bits. The first fragment is transmitted from the source node to the relay node at a first data rate during a first phase. The second fragment is transmitted from the source node to the destination node at a second data rate during a second phase while the first fragment is retransmitted from the relay node to the destination node at a third data rate.

Abstract: A method allocates resources in an orthogonal frequency-division multiple access (OFDMA) network including a set of base stations (BSs), and a set of mobile stations (MSs) for each BS. Each cell includes a center and edge zone. A node weighted constraint graph is constructed for the network. Maximal independent sets in the graph are searched as sub-channels are allocated to the MSs in edge zones. Remaining bandwidth is allocated to the MSs in the center zones. Power is assigned to the sub-channels so that inter-cell interference is minimized and traffic load is maximized.

Abstract: A method selects an optimal route in a cooperative relay network including a set of nodes. For each node in a set of nodes of a cooperative relay network, dynamically varying channel state information is determined. A transmission policy based on the dynamically varying channel state information is selected, in which the transmission policy includes selected nodes forming an optimal route, a transmission mode for each selected node, and a transmission power for each selected node.

Abstract: A method and system switches antennas in an orthogonal frequency division multiplexed access (OFDMA) wireless communication system while transmitting symbols. Each symbol includes a cyclic prefix and a block of data signals. The symbols are transmitted during a first portion of a transmission time interval (TTI), from a first antenna. Then, the RF chain is switched to a second antenna to transmit the symbols, and in which the switching is performed substantially between transmitting two consecutive transmitted symbols.

Abstract: A method and system for communicating information in a cooperative relay network of wireless nodes. The wireless nodes including a source, a set of relays, and a destination. Channel state information for each channel between a particular relay of the set of relays and the destination is estimated. A subset of the relays is selected based on the channel state information. The channel state information is fed back to the subset of relays. The source node can then broadcasting data packets from the source to the subset of relays, and the subset of relays forward coherently the data packets from the subset of relays to the destination using beamforming based on the channel state information, while adjusting power to minimize a total energy consumption in the network.

Abstract: A method allocates frequency subchannels in an orthogonal frequency-division multiple access (OFDMA) network including a set of base stations and a set of mobile stations for each base station. A graph of nodes and edges is constructed, in which the nodes represent the mobile stations in the network, and the edges connecting the nodes represent subchannel allocation constraints to be satisfied for the mobile stations represented by the nodes. The nodes are colored with colors selected from a set of colors such that subchannel allocation constraints of a pair of nodes connected by one of the edges are satisfied. The subchannels are allocated to the mobile stations according to the colors of the corresponding the nodes.

Abstract: The invention provides a system and method for effectively reducing peak-to-average power ratio (PAPR) in an OFDM signal. The method includes the steps of oversampling a signal in the time domain, gradually clipping an amplitude of the signal to a predefined level using a formula involving a hyperbolic tangent, bandpass filtering out-of-band spectral components of the signal due to non-linear clipping to be within a predetermined mask, and transmitting the signal.

Abstract: A system and method for communicating information in a wireless cooperative relay network of nodes, the nodes including a source, a set of relays, and a destination. The source broadcasts a code word encoded as a data stream using a rateless code. The relays receive the data stream, decode the data stream to recover the code word, and reencode and transmit the recovered code word as the data stream with the rateless code. The destination receives and decodes the reencoded data streams to recover the code word.

Abstract: Embodiments of the invention describe a method for joint resource blocks assignment and antenna selection (AS) in a wireless communication network, the network comprising user equipment (UE), wherein the UE comprises a plurality of subsets of antennas, 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 a first subset of antennas and a second SRS from a second subset of antennas. Upon receiving, in response to the transmitting of the first SRS and the second SRS, information related to an optimal subset of antennas, and information related to an optimal subset of resource blocks, the method transmits a data symbol from the optimal subset of antennas using the optimal resource block.

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: 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 and system enables and improves performance of hybrid automatic repeat request (HARQ) operations on channels between stations of an orthogonal frequency division multiple access (OFDMA) wireless communication network. There, the number of parallel HARQ channels is increased adaptively, and one connection identifier is used to unambiguously identify a set of MAC protocol data units (MPDUs) communicated over parallel HARQ channels. A sequence number is used to avoid out-of-order MPDU delivery when MPDUs are transmitted over parallel HARQ channels. The MPDUs can be concatenated or encapsulated. The maximum number of the parallel HARQ channels can be increased to 256, and can be negotiated when a station enters or re-enters the network.

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: 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 movable portion of an array of antenna elements receives RF signals. A movable ultra-wideband (UWB) transmitter is connected to each antenna element, via a RF to UWB converter. A fixed portion of the antenna array is separated from the movable portion by an air gap. The fixed portion includes one fixed UWB receiver for each movable UWB transmitter. An application system is connected to the fixed UWB receivers. The UWB signals from the movable transmitter are sent across the air gap to the fixed UWB receivers to be processed by the application system as the movable portion rotates.