Abstract: A method and apparatus for selectively enabling or disabling transmit diversity in a mobile communication device. The mobile communication device may switch between diversity and non-diversity operation based on various transmit power considerations.

Abstract: A mobile communication device and a method of controlling same, in which the mobile communication device transmits a plurality of transmit diversity signals comprising a first transmit signal and a second transmit signal differing at least by values of a transmit diversity parameter, receives a plurality of feedback signals from at least one base station in response to the plurality of transmit diversity signals; and determines a system delay based on detecting that a number of expected feedback signal patterns among the received plurality of feedback signals exceeds a system delay threshold.

Abstract: Embodiments of the present invention may separately utilize transmit paths of a mobile transmit diversity device to initialize communication with a base station over a random access channel, particularly where the transmit paths have power amplifiers with different characteristics, e.g., different power amplification.

Abstract: A transmit amplifier stage operable to amplify a transmit signal comprises power amplifiers and switches. The power amplifiers include at least one fractional power amplifier operable to provide fractional power to amplify the transmit signal, where the fractional power is a fraction of the full power. A switch has a plurality of positions, where a position directs the transmit signal to a selected power amplifier.

Abstract: A method and system for improving closed loop feedback in transmit diversity communication. In one embodiment of the invention, a predetermined variation of one or more transmit diversity parameters is performed at the transmit diversity transmitter. The receiver compares the transmit diversity parameter values of the received signals to the predetermined variation and transmits to the transmitter a value of a transmit diversity correction parameter. The transmitter may use this correction value to modify the transmit diversity parameter in a subsequent transmission.

Abstract: Embodiments of the present invention describe methods for increasing the amount of information available to a mobile transmit diversity transmitter during soft handoff. According to embodiments of the invention, a transmit diversity transmitter may determine substantially when it is within the range of at least two receivers. In such situations, the transmitter may use the power control signals from more than one receiver, for example, from the two most dominant receivers in order to focus the beamforming accordingly.

Abstract: A device, system, and method for providing a transmit diversity device have a first antenna and a second antenna. The first antenna may have a first power transmission gain pattern, which may be non-uniform in a reference plane. The second antenna may have a second power transmission gain pattern, which may be non-uniform in a reference plane. The first and second antennae may be arranged with respect to each other such that a minimum power region of the first gain pattern overlaps a maximum power region of the second gain pattern in the reference plane. The transmit diversity device may also have a processor to receive a feedback parameter from a feedback device. The processor may produce a different transmit diversity parameter based on the feedback parameter for each of a first and second signals to be transmitted on the first and second antennae, respectively.

Abstract: Embodiments of the present invention describe methods for increasing the amount of information available to a mobile transmit diversity transmitter during soft handoff. According to embodiments of the invention, a transmit diversity transmitter may determine substantially when it is within the range of at least two receivers. In such situations, the transmitter may use the power control signals from more than one receiver, for example, from the two most dominant receivers in order to focus the beamforming accordingly.

Abstract: A method and system for improving closed loop feedback in transmit diversity communication. In one embodiment of the invention, a predetermined variation of one or more transmit diversity parameters is performed at the transmit diversity transmitter. The receiver compares the transmit diversity parameter values of the received signals to the predetermined variation and transmits to the transmitter a value of a transmit diversity correction parameter. The transmitter may use this correction value to modify the transmit diversity parameter in a subsequent transmission.

Abstract: A method, system and apparatus for determining at least one relative characteristic of a transmit diversity transmitter based on at least one quality indicator based on signals received on the plurality of antennas. In some embodiments of the invention, the relative characteristic may be a relative power or amplitude ratio and/or a phase difference between the signals transmitted on the different antennas.

Abstract: A transmit amplifier stage operable to amplify a transmit signal comprises power amplifiers and switches. The power amplifiers include at least one full power amplifier operable to provide full power to amplify the transmit signal and at least one fractional power amplifier operable to provide fractional power to amplify the transmit signal, where the fractional power is a fraction of the full power. A switch has a plurality of positions, where a position directs the transmit signal to a selected power amplifier.

Abstract: A method, system and apparatus using hybrid automatic repeat-request (HARQ) to enhance a system throughput in a transmit diversity system.

Abstract: A receiver, or base station, may calculate the signal quality improvement based on a change in a diversity control parameter, for example, a phase difference or a power ratio among two or more antennas, by comparing a received signal power level to an expected power level, assuming no change in fading characteristics at the previous timeslot. This method may increase the amount of information communicated between the base station and the mobile unit, and may reduce feedback response time and/or provide for more efficient feedback for transmit diversity systems.

Abstract: A system may include a modifiable mobile device having at least two antennas coupled to fractional amplifiers, with returned power detectors. A beamformer unit provides adaptive beam shaping pattern, and a baseband processor provides beam pattern requirements, wherein the beamformer unit modifies the beam pattern requirements with return loss sampling information to shape the adaptive beam pattern so that a transmitted beam pattern minimizes transmitted power reflected back to the mobile device. A method may include regularly measuring a return power level, if output power is greater than a specific absorption rate level, comparing the return power level to a first threshold, else implementing mobile transmit diversity (MTD), and repeating. If the return power level is greater than the first threshold, implementing a MTD combined with reflection-based beamforming that modifies beam pattern requirements of the mobile device with return loss sampling information to create an adaptive beam pattern.

Abstract: Embodiments of the present invention include a method and apparatus for modifying a transmit diversity signal by control of at least a relative parameter, for example, phase difference, in a first signal relative to at least one second signal using various switching modules or techniques. In some embodiments of the invention, the relative difference may be controlled by switching paths, or producing various degrees of relative difference by switching, activating or controlling multiple elements with various resolutions of the relative parameter, or by connecting elements by timing of switches.

Abstract: Communication is performed for a first communication device having a set of antenna elements. A quality-indication signal is received from a second communication device (e.g., a basestation). A complex weighting is calculated based on the quality-indication signal. A pre-transmission signal is modified based on the complex transmit diversity weighting to produce a set of modified-pre-transmission signals, wherein the modifications are symmetric by making approximately half the magnitude of the transmit diversity modification to one signal in a first direction, and approximately half the magnitude of the transmit diversity modification to the other signal in a second direction, opposite the first direction. Each modified pre-transmission signal from the set of modified-pre-transmission signals is uniquely associated with an antenna element from the set of antenna elements. The set of modified-pre-transmission signals is sent from the set of antenna elements to produce a transmitted signal.

Abstract: A signal is modified according to a current diversity parameter adjustment, and is transmitted from a modifying communication device to a feedback communication device. A feedback signal reflecting feedback information describing the signal as received by the feedback communication device is received. The feedback signal comprises frames, and a frame comprises slots, where a slot has a slot power value. The frame timing of the frames is established from the slot power values. The signal is modified according to a next diversity parameter adjustment in accordance with the frame timing.

Abstract: A mobile communication device may transmit a signal using a plurality of antenna elements, the signals differing by a transmit diversity parameter, e.g., a phase difference. The mobile communication device may receive a quality-indication signal from a basestation, e.g., a power control bit or signal. A sequence of the power control bits or signals may be used to provide feedback to the mobile communication device to determine a change in a transmit diversity parameter.

Abstract: Communicating a signal includes establishing a quality indicator at a first communication device that has antenna elements. The quality indicator indicates the quality of communication links between the first communication device and a second communication device. A modification describing an adjustment of a modulation feature is determined according to the quality indicator. The availability of the quality indicator is established. Modulation of a subset of signals in accordance with the determined modification is initiated in response to establishing the availability of the quality indicator. The antenna elements send the signals to yield a transmitted signal.

Abstract: Modifying a signal according to a diversity parameter adjustment includes accessing scan parameter values, where a scan parameter describes a scan process. The scan parameter values include diversity parameter vectors, where a diversity parameter vector has a diversity parameter value for each of one or more diversity parameters. The scan process is performed by repeating the following for each diversity parameter vector: modifying a signal according to the diversity parameter values of the diversity parameter vector, where the signal is transmitted from a modifying communication device to a feedback communication device; and receiving a feedback signal reflecting feedback information describing the signal as received by the feedback communication device.