Motorola Corporation

Motorola Mobility LLC

Shahriar Emami

Salvador Sibecas

Glafkos K Stratis

Celestino Anastasio Corral

Gregg E Rasor

Richard S Young

Rudy Michael Emrick

Charles H Carter

Jianping W Miller

Julio C Blandon

Alejandro G Blanco

A system () and method () for ray launching is provided. The system can include a transmitter () for successively launching a plurality of rays, and a receiver () for receiving transmission rays and reflection rays. A controller () can be included for selectively adjusting an angular spacing and eliminating rays in successive launches to focus an energy on the receiver. A method () of terminating rays for reducing computational complexity is provided. A method () for ray weighting for increasing a computational speed of ray propagation is provided. In one aspect, a quality of service () can be determined at the receiver based on ray propagation.

Method and system for adaptive ray launching

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 () 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 () transmits the first portion of the data as a set of first OFDM subcarriers using an antenna () exhibiting a first polarization. A second transmitter () transmits the second portion of the data as a set of second OFDM subcarriers using an antenna () exhibiting a second polarization, wherein the first polarization is orthogonal to the second polarization. A receiver apparatus uses a first antenna () exhibiting the first polarization and a second antenna () exhibiting the second polarization. A first OFDM receiver () receives a first set of polarized OFDM subcarriers from the first antenna () while a second OFDM receiver () receives a second set of polarized OFDM subcarriers from the second antenna (). A decoder () decodes the first and second sets of OFDM subcarriers and combines them into a stream of data.

Enhanced OFDM by use of alternating polarization states

A technique is used in a wideband wireless communication system (). In some embodiments available channels are determined () and one is selected () 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 () a channel selected from among available channels and a relative signal loss parameter of the communication unit, such as transmit power, is adjusted (), based on a relative frequency path loss determined from the channel frequency of the assigned channel. In other embodiments, transmit information is split () into a plurality of data streams, each characterized by an associated relative signaling sensitivity, and each data stream is assigned () 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.

Method and communication unit for use in a wideband wireless communications system

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.

Polarization state techniques for wireless communications

An antenna system () includes an antenna structure (), a receiver (), and an antenna system controller (). The antenna structure includes an arrangement of antennas (), a signal combiner (), and a switching matrix (). 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 (), (), (), (), () 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.

Adaptive diversity antenna system

A technique for constructing a dictionary word list for use in a data compressor is provided by determining a set of words that are included in the dictionary word list and sorting each subset of words having a common starting character by lengths of the words. Partitions are formed and identified based on the common starting character and word length, with each partition being stored in memory and indexed.

Text compression method and apparatus

An FM demodulator in accordance with the present invention receives a composite signal from an antenna and corresponding processing circuitry. The composite signal includes a carrier signal having a voice/data signal modulated thereon. The composite signal is processed to separate the voice/data signal from the carrier signal. The voice/data signal is separated into an in-phase (I) signal and a quadrature (Q) signal. The Q signal is differentiated and then divided by the I signal to obtain the voice/data signal. Alternatively, I signal is differentiated and then divided by the Q signal to obtain the voice/data signal.

Differentiate and divide FM demodulator

A multicarrier transmission system (100) routes data symbols from a data source (142) to a multicarrier modulator (145). Each modulator (201, 202, 203) within the multicarrier modulator (145) is coupled to a corresponding gain adjuster (211, 212, 213) that distributes the available transmit power across various subcarriers. Power distribution, is determined in part, upon the noise sensitivity of the transmitted information. In accordance, data stream symbols of like sensitivity are grouped (520) and transmitted during defined time intervals. Each such group is assigned a unique transmission power level (530). At any given moment in time, all subcarrier transmission power levels will have an identical amplitude, thereby mitigating the impact of subchannel-to-subchannel interference.

Time domain source matched multicarrier quadrature amplitude modulation

A radio device requires a tunable transceiver such that the transceiver can be accurately set to a desired frequency. When a signal with known frequency accuracy is being received, an offset detector can determine the frequency offset generated by the transceiver due to improper tuning. An automatic frequency control (AFC) system (100) is comprised of a tunable transceiver, an offset detector (103) and an AFC control processor (105) for utilizing information from the offset detector to reduce the inaccuracy in frequency by tuning the transceiver towards the received signal frequency. The AFC control processor (105) utilizes one of more threshold levels for defining a maximum correction threshold (311) based upon the desired maximum offset correction. These thresholds are used by the AFC control processor (105) to efficiently control the predetermined frequency range of the tunable transceiver (101) for most efficient operation.

Automatic frequency control system using multiple threshold levels and

A communication device (100) includes an equalizer (126) for correcting imbalance between in-phase and quadrature components of a received signal. The equalizer (126) determines peak amplitude for the in-phase and quadrature components, and the phase imbalance between both components (440). At least one of the in-phase and quadrature components is adjusted based on a function of the phase imbalance, and of the ratio of peak amplitudes of the in-phase and quadrature components (450, 460).

Method and apparatus for correcting phase and gain imbalance between

A multicarrier transmission system (100) supports different desired error rates within a data symbol stream by manipulating subcarrier transmission characteristics for multiple subcarriers. A data symbol stream obtained for transmission is segmented into multiple substreams, and assigned to subcarriers based on error protection requirements (310, 320, 330). The transmission characteristics of the subcarriers are manipulated, according to a selected transmission configuration, to effect the combined error protection requirements (350, 360). Preferably, the subcarriers are modulated by allocating available power based on the relative error protection required for the substreams (360).

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Royal Palm Beach, FL, United States of America

Shahriar Emami