Abstract:
A wireless communication system having portable communication devices capable of establishing direct terminal-to-terminal communication through another terminal without having a fixed base station. A portable communication device used as a terminal is capable of functioning as a router for other communication devices while maintaining separated communications with another device. Upon registration (904, figure 9), the device searches the device begins the process of communication by discovering other devices (906).
Abstract:
Communication systems include a transmitter that modulates a radio signal transmitted from two differently polarized antennas during a state time in which a wave state of the radio signal conveys information and is based on one or more polarization states selected from a constellation of polarization states comprising at least three polarization states. The communication system includes a receiver that intercepts the radio signal by two differently polarized antennas during the state time, and demodulates the signal. The polarization states may identify user devices or may quantify a portion of the information intended for a user device.
Abstract:
A method (20 or 500) and system (200) for method for computing wireless signal diffraction in a three-dimensional space can include the steps of selecting at least a source point, finding (19) sinkpoints that fail to have a line-of-sight path to the source point and storing the sinkpoints found, placing (21) diffraction points on all edges of a three-dimensional geometry, and building (24) a visibility matrix based on weighted paths for all source points and all sink points. The method can further include applying (25) a path finding algorithm on the visibility matrix for each sink point to all source points and storing store optimal paths for each source point to all sink points if they exist. The method can further include determining (23) if a last source point is selected before building the visibility matrix.
Abstract:
A system (170) and method (300) for ray launching is provided. The system can include a transmitter (110) for successively launching a plurality of rays, and a receiver (120) for receiving transmission rays and reflection rays. A controller (141) can be included for selectively adjusting an angular spacing and eliminating rays in successive launches to focus an energy on the receiver. A method (430) of terminating rays for reducing computational complexity is provided. A method (340) for ray weighting for increasing a computational speed of ray propagation is provided. In one aspect, a quality of service (108) can be determined at the receiver based on ray propagation.
Abstract:
An Orthogonal Frequency Division Multiplexer (OFDM) transmitter and receiver apparatus consistent with certain embodiments of the present invention maps (204) a first portion of data to be transmitted to a first polarization state and a second portion of the data to a second polarization state. A first transmitter (216) transmits the first portion of the data as a set of first OFDM subcarriers using an antenna (230) exhibiting a first polarization. A second transmitter (234) transmits the second portion of the data as a set of second OFDM subcarriers using an antenna (240) exhibiting a second polarization, wherein the first polarization is orthogonal to the second polarization. A receiver apparatus uses a first antenna (302) exhibiting the first polarization and a second antenna (306) exhibiting the second polarlization to receive and decode first and second sets of OFDM subcarriers and combines them into a stream of data.
Abstract:
A WLAN communication system (10) and method employs mobile WLAN base stations (16) that include WLAN transceivers (26) and memory (30) for storing received messages from one or more mobile WLAN devices (12a-12n). The mobile WLAN base stations (16) serve as moving message carriers or message repeaters of messages for the mobile WLAN devices. In one embodiment, a mobile WLAN base station (16) receives messages transmitted by several mobile WLAN devices (12a-12n), temporarily stores the received messages, and delivers the stored messages to a fixed WLAN base station or another mobile WLAN base station when the mobile WLAN base station (16) moves to within communication range of the applicable fixed or other mobile WLAN base station.
Abstract:
A method for sending messages from a particular device to one or more other devices communicants (300) uses the relative geographic location of the targeted devices as addressing criteria. The particular device forms or joins a network of potential communicants, and exchanges information to determine their relative geographic location with respect to that of the particular device (310, 320). The relative geographic location is preferably defined by a directional component and a range component. The communication device then selects for communication those devices that meet specific criteria, such as a specific direction and range, and transmits a message to the selected devices (330, 332, 334, 336).
Abstract:
A technique is used in a wideband wireless communication system (100). In some embodiments available channels are determined (310) and one is selected (315) for assignment to each of a set of communication units based on a relative frequency path loss for each available channel. In some embodiments a communication unit is assigned (505) a channel selected from among available channels and a relative signal loss parameter of the communication unit, such as transmit power, is adjusted (510), based on a relative frequency path loss determined from the channel frequency of the assigned channel. In other embodiments, transmit information is split (705) into a plurality of data streams, each characterized by an associated relative signaling sensitivity, and each data stream is assigned (715) to one of a plurality of the transmit channels, wherein data streams are assigned channels of decreasing channel frequencies in order of decreasing associated relative signaling sensitivities of the data streams.
Abstract:
An antenna system (205) includes an antenna structure (215), a receiver (220), and an antenna system controller (225). The antenna structure includes an arrangement of antennas (237), a signal combiner (240), and a switching matrix (235). The arrangement of antennas is designed to have a set of antenna element separations that are optimized to provide lowest correlation coefficients of intercepted radio signals for a corresponding set of electromagnetic environment types that vary from a very low density scattering environment to a maximum density scattering environment. The antennas (230), (231), (232), (233), (234) in the antenna arrangement each include at least one element that has a common polarization. There is at least one antenna that is a dual polarized antenna. The antenna system selects an antenna element pair that corresponds to the environment type which it is operating and thereby receives a best combined signal.
Abstract:
A technique is used in a wideband wireless communication system (100). In some embodiments available channels are determined (310) and one is selected (315) for assignment to each of a set of communication units based on a relative frequency path loss for each available channel. In some embodiments a communication unit is assigned (505) a channel selected from among available channels and a relative signal loss parameter of the communication unit, such as transmit power, is adjusted (510), based on a relative frequency path loss determined from the channel frequency of the assigned channel. In other embodiments, transmit information is split (705) into a plurality of data streams, each characterized by an associated relative signaling sensitivity, and each data stream is assigned (715) to one of a plurality of the transmit channels, wherein data streams are assigned channels of decreasing channel frequencies in order of decreasing associated relative signaling sensitivities of the data streams.