Abstract:
PROBLEM TO BE SOLVED: To provide a method for achieving transmit and/or receive diversity using multiple antennas.SOLUTION: A single transmitter chain within a wireless terminal is coupled over time to a plurality of transmit antennas 312. At any given time, a controllable switching module 310 couples the single transmitter chain to one of the plurality of transmit antennas. Over time, the switching module couples the output signals from the single transmitter chain to different transmit antennas. Switching determinations are based upon predetermined information, dwell information, and/or channel condition feedback information. Switching is performed on some dwell and/or channel estimation boundaries. Each of multiple transmitter chains is coupled to a different transmit antenna. Information to be transmitted is mapped to a plurality of tones.
Abstract:
PROBLEM TO BE SOLVED: To provide wireless terminal beacon signaling which achieves timing synchronization between two wireless terminals in a wireless communication system, e.g., in an ad hoc network lacking a centralized timing reference.SOLUTION: A timing structure used by an individual wireless terminal includes a beacon transmission time interval, a beacon monitoring time interval and a silence time interval. A first wireless terminal that monitors beacon signals from other wireless terminals detects a beacon signal portion from a second wireless terminal and determines a timing adjustment as a function of the detected beacon signal portion. The first wireless terminal applies the determined timing adjustment, e.g., time shifting of its timing structure, so that its beacon signal can be detected by the second wireless terminal. Implementation of the determined timing adjustment sets the timing structures of the two wireless terminals to have a fixed relationship, thereby allowing for coordinated communications including a peer-to-peer communications session.
Abstract:
PROBLEM TO BE SOLVED: To provide a method and apparatus for wireless network connectivity.SOLUTION: Methods and apparatus which allow a wireless terminal (302) to simultaneously maintain connections with multiple base stations (304, 306) are described. Each wireless terminal (302) is capable of supporting multiple separate timing loops and/or other control loops for each base station connection, thereby allowing the connections to operate independently and in parallel. Different control signals and/or data are transmitted on each connection that is established with a base station (302, 306). In this manner, base stations (302, 306) receive different data allowing asynchronous data transmission. The data received by the base stations (302, 306) can be supplied to a wired asynchronous network (308) without the need to combine the received data prior to supplying it to the wired network (308). The communications techniques of the invention can be used to implement soft handoffs without the need to duplicate data transmissions to multiple base stations.
Abstract:
PROBLEM TO BE SOLVED: To provide methods and apparatus for routing messages between an end node and an access node via another access node.SOLUTION: Physical layer identification information is used when identifying a remote, e.g., adjacent, access node as a message destination. Thus, when a connection identifier based on one or more physical layer identifiers is available to a wireless terminal, e.g., from one or more downlink signals received from a destination access node, the wireless terminal can use the connection identifier corresponding to the destination node to route a message via an access node with which it has an established uplink connection. Such connection identifier information can be used even when other addressing information, e.g., network layer address information, associated with the destination access node, may not be available to the wireless terminal.
Abstract:
PROBLEM TO BE SOLVED: To provide methods and apparatus related to the sharing of wide area network (WAN) uplink bandwidth with peer to peer communication signaling usage.SOLUTION: A base station uses its WAN uplink band to receive uplink signals from wireless terminals using the base station as an attachment point. In accordance with a feature, a base station injects a beacon signal into its WAN uplink bandwidth, e.g., its WAN frequency division duplex (FDD) uplink band. A peer to peer wireless terminal scans the uplink bandwidth, detects the base station signal, evaluates the received base station signal, and controls peer to peer transmission as a function of the evaluation. Control of peer to peer transmission includes adjusting peer to peer transmission power as a function of the evaluated base station signal. The communications band used for peer to peer communications is, in some embodiments, the same uplink band.
Abstract:
PROBLEM TO BE SOLVED: To provide improved ways for synchronization of terminals in a system in which a network infrastructure is not available.SOLUTION: Peer to peer communication timing, e.g., for an ad hoc network, is referenced with respect to an external broadcast signal from a terrestrial or satellite based transmitter. Wireless terminals, seeking to communicate via peer to peer communications, receive the reference broadcast signal, and set their internal timing structure with respect to the reference signal. This facilitates peer to peer timing coordination. A wireless terminal transmits a signal, e.g., a user beacon signal identifying its presence, during a time interval during which another wireless terminal is expected to be monitoring. Reference signal based coordinated timing and use of user beacon signals allow the wireless terminals to maintain situational awareness and coordinate peer to peer communications, while keeping power consumption low.
Abstract:
PROBLEM TO BE SOLVED: To provide transmission techniques using configurable channels for the downlink and/or uplink.SOLUTION: The downlink channel and/or uplink channel may be independently selected for a terminal. The terminal may establish a connection with a base station on default downlink and uplink channels. Another downlink channel and/or another uplink channel may be selected based on various factors such as channel quality, loading, and interference. The terminal would then switch to the new downlink and/or uplink channel for communication.
Abstract:
PROBLEM TO BE SOLVED: To establish the timing synchronization of a wireless terminal using OFDM signaling supporting connectivity with both of a terrestrial base station and a satellite base station. SOLUTION: The OFDM signal is used in the synchronization processing for uplink signaling and downlink signaling to perform first uplink timing synchronization processing for determining whether a base station to which the communication terminal desires to transmit an OFDM uplink signal is the satellite base station, and second uplink timing synchronization processing which is different from the first uplink timing synchronization processing for determining whether the base station is the terrestrial base station. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide methods and apparatus for selecting between multiple carriers based on signal energy measurements. SOLUTION: Although a receiver is tuned to a single band, based on the relative energy of beacon signal components corresponding to the currently used carrier and beacon signal components corresponding to an alternative carrier, a carrier selection and a handoff determination are made. Mobile nodes receive a signal within a first selected carrier band including components from different transmitters, e.g., a first signal component identified with the first currently selected band and a second signal component identified with a second alternative band. The signal components, e.g., beacon signal components from different transmitters may be obtained from a signal which corresponds to multiple symbol transmission time periods. Separate signal energy measurements are performed on the first and second signal components. The signal component energy is compared, and a determination is made as to whether a handoff should be initiated. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide methods and apparatuses for determining, communicating and using information which can be used for interference control purposes. SOLUTION: Wireless terminals measure signals transmitted from one or more base stations, e.g., base station sector transmitters (1010, 1014). The measured signals may be, e.g., beacon signals and/or pilot signals. From the measured signals, the wireless terminal generates one or more gain ratios which provide information about the relative gain of the communications channels from different base station sectors to the wireless terminal (1018). On the basis of signal energy measurements and relative gains generated from the energy measures, reports are generated and sent to one or more base stations. COPYRIGHT: (C)2011,JPO&INPIT