Abstract: An Orthogonal Frequency Division Multiplexer (OFDM) transmitter and receiver apparatus consistent with certain embodiments of the present invention receives data to be transmitted and maps (204) a first portion of the data 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 polarization.

Abstract: An improved method for determining an initial flat spot magnitude on a tire that has been resting for a period of time on a substantially flat surface uses regression analysis. In accordance with the method, values of a tire flat spot magnitude for a particular type of tire are determined at a number of measurement intervals by a uniformity machine that spins the tire. An equation having at least two exponentially decaying terms is then determined that corresponds to the measured data points. Regression analysis is then used to determine an estimate for an initial flat spot magnitude. The method can be used to evaluate the effectiveness of different tire designs with respect to flat spot recovery rates.

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: An improved method for determining an initial flat spot magnitude on a tire that has been resting for a period of time on a substantially flat surface uses regression analysis. In accordance with the method, values of a tire flat spot magnitude for a particular type of tire are determined at a number of measurement intervals by a uniformity machine that spins the tire. An equation having at least two exponentially decaying terms is then determined that corresponds to the measured data points. Regression analysis is then used to determine an estimate for an initial flat spot magnitude. The method can be used to evaluate the effectiveness of different tire designs with respect to flat spot recovery rates.

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 orthogonal frequency division multiplexing (OFDM) transmitter method, consistent with certain embodiments of the present invention arranges OFDM data symbols representing data bits for transmission in a packet. A prescribed pattern of OFDM data symbols are removed (212) and replaced (216) with pilot symbols. The packet is then transmitted (220) to an OFDM receiver that receives the packet (224) and determines a channel correction factor from the pilot pattern. The receiver then estimates a plurality of channel correction factors, one for each of the plurality of OFDM symbols representing data (228) and uses these correction factors to correct the OFDM symbols representing data (232). Arbitrary data are then inserted in place of the pilot symbols (236). The OFDM symbols representing data along with the arbitrary data are then decoded using an error correction decoder that corrects the errors induced by substitution of the pilot symbols for data symbols (240).

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: An Orthogonal Frequency Division Multiplexer (OFDM) transmitter and receiver apparatus consistent with certain embodiments of the present invention receives data to be transmitted and maps (204) a first portion of the data 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 polarization.

Abstract: An orthogonal frequency division multiplexing (OFDM) transmitter method, consistent with certain embodiments of the present invention arranges OFDM data symbols representing data bits for transmission in a packet. A prescribed pattern of OFDM data symbols are removed (212) and replaced (216) with pilot symbols. The packet is then transmitted (220) to an OFDM receiver that receives the packet (224) and determines a channel correction factor from the pilot pattern. The receiver then estimates a plurality of channel correction factors, one for each of the plurality of OFDM symbols representing data (228) and uses these correction factors to correct the OFDM symbols representing data (232). Arbitrary data are then inserted in place of the pilot symbols (236). The OFDM symbols representing data along with the arbitrary data are then decoded using an error correction decoder that corrects the errors induced by substitution of the pilot symbols for data symbols (240).

Abstract: A radio frequency field strength enhancement system (402) having a member (404) with at least one tuning impedance (405) for adjusting a desired frequency response associated with the member (404) and means for retaining (408) the member (404) in close proximity to a radio frequency communication device (401) having an integrally mounted antenna system (214). When the radio frequency communication device (401) is brought within close proximity of the RF field strength enhancer (402), the power received or transmitted by the integrally mounted antenna system (214) in the RF communication device (401) is enhanced.