Abstract:
A wireless mobile terminal for a wireless communication system comprises a wireless transceiver, a global positioning system (GPS) receiver, wherein the wireless transceiver and the GPS receiver share a frequency reference signal. The frequency reference signal can be multiplied by an integer multiple to create a first local oscillator for a signal conversion to an intermediate frequency for signal processing of the GPS signal. In addition, the frequency reference signal can also be divided into a lower frequency to create a second local oscillator for a conversion to a second intermediate frequency. The frequency reference signal can also be divided to create a frequency necessary for other signal processing, such as an analog-to-digital converter sampling signal at the GPS receiver. The frequency reference signal can be taken from different places within the frequency synthesis mechanism of the wireless transceiver. For example, in one embodiment the frequency reference signal is a reference oscillator signal, in another embodiment the frequency reference signal is a radio frequency signal, and in yet another embodiment the frequency reference signal is a radio frequency control signal. Frequency error can be removed from the frequency reference signal by locking to a base station carrier.
Abstract:
The present invention discloses an apparatus and method for tuning an oscillator to a selected frequency during power measurements of a neighbor list. In response to a received request for the oscillator to tune to a selected frequency, a controller associated with a switch determines whether the request comprises a first request for the oscillator to tune to the selected frequency. If so, the switch is placed in a first position, and the oscillator is provided a voltage control signal from a phase locked loop. The voltage control signal applied to the input of the oscillator is also saved at a location associated with the selected frequency. If the controller determines that the request does not comprise a first request for the selected frequency, a previously saved voltage control signal associated with the selected frequency is applied to the input of the oscillator by placing the switch in a second position. In either case, the oscillator is tuned to the selected frequency responsive to the applied voltage control signal.
Abstract:
A power amplifier uses a modulation technique that varies amplitude of a drive signal and, optionally, phase angle of the drive signal. The power amplifier comprises two coupled amplifiers, a first one of which is operated saturated to produce a constant voltage output. The first amplifier is coupled to a second one of the amplifiers via a quarter wave transmission line. The second amplifier is operated in a linear mode to deliver an output signal controlled by an amplitude-modulating signal. The amplitude-modulating signal may be a bipolar modulation signal that produces both positive and negative outputs from the second amplifier that add to or subtract from the output from the first amplifier to develop at a load impedance net output signal amplitudes varying between a minimum or “trough” amplitude and a maximum or “crest” amplitude. The coupling of the first and second amplifiers through a quarter-wave line allows the signal current of the second amplifier to modulate the effective load impedance seen by the first amplifier to provide efficient amplifier coupling.
Abstract:
A method and apparatus for determining the capacity in a battery-powered communication. The method includes the steps of measuring a temperature of the battery, measuring a charging voltage and current, and determining a value corresponding to the number of charge cycles associated with the battery. Using these parameters, a capacity value corresponding to at least one of the parameters is computed based on stored database information. The apparatus includes a microprocessor linked to the battery. The microprocessor estimates the capacity present in the battery and calculates the remaining amount of battery capacity. After determining the present mode of battery power discharge, the microprocessor calculates the remaining available power time for the battery corresponding to previously read operational parameters.
Abstract:
Modulation systems and methods can modulate a stream of complex numbers representing a desired modulation of a radio signal by representing a real part of each of the complex numbers in a stream of complex numbers representing a desired modulation of a radio signal, as a plurality of first digits of decreasing numerical significance and representing an imaginary part of each of the complex numbers as a plurality of second digits of decreasing numerical significance. A respective one of the first digits and a respective one of the second digits of like numerical significance are grouped to form a plurality of phase control symbols. A respective phase control symbol is then used to control the phase of an output signal at the radio carrier frequency from a respective one of the plurality of power amplifiers. Each of the power amplifiers provides an output power level that is related to the numerical significance of the first and second digits that form the associated phase control symbol. The output power levels of the plurality of power amplifiers are combined to thereby form the modulated radio power signal.
Abstract:
An RF amplifier includes an oscillator developing an RF input signal to be transmitted. A power amplifier receives the RF input signal and amplifies the RF input signal to develop an RF output signal. An amplifier control is operatively associated with the oscillator and the power amplifier. The amplifier control includes means for developing a control signal representing a desired amplitude of the RF output signal. A memory stores correction information correlating actual amplitude of the RF output signal relative to the control signal, and a control varies the power amplifier circuit supply voltage using the control signal modified responsive to the correction information for the desired amplitude.
Abstract:
A system for locating a mobile transceiver is disclosed. A first receiver associated with a mobile transceiver detects signals transmitted from fixed transmitter locations broadcasting, for example, FM signals. A demodulated audio portion of the received FM signals, along with an encoded representation of the channel of the transmitted FM signal, are transmitted to a second receiver at a known location. The second receiver is tuned to the channel indicated by the channel data. A correlator time-shifts the received audio portion of the FM signal until a correlation with the received signal at the second receiver is achieved. This process may be repeated for several transmitted FM signals. The time differences between the signals received at the first and second receivers along with the known location of the FM transmitters are used to determine the location of the mobile unit.
Abstract:
An apparatus for massive computation in integrated circuits provides the ability to calculate multiple dot products between an image focused on the integrated circuit surface and many reference patterns built into the integrated circuit, and then give an output indication for all those reference patterns where the dot product exceeds a threshold. The implementation, using current mirrors for multiplication with fixed constants, permits the integrated circuit to achieve large amounts of computation per unit area. This apparatus permits a large input data bandwidth, and by virtue of having enough computation capacity to complete a processing task on one chip, the output bandwidth is greatly reduced as well. The apparatus is employed, as an example, in a neural network. A set of connections between nodes that modify the value of the signal passed from one node to the next. Often many connections impinge on a node, and the summation of values at the node is further modified by a nonlinear function such as a threshold and amplitude limiter. Values at the input nodes represent the signals to be evaluated by the network, and values at the outputs represent an evaluation by the network of the input signals. For instance, the input could be image pixels and the outputs could represent possible patterns to which the image could be assigned. The connections between weights are often determined and modified by training data, but they can also be prespecified in total or in part based on other information about the task of the network.
Abstract:
Methods of delivering electronic content include exchanging communications with a network access point from a control terminal to establish a communication link configured for two-way communications. Electronic content transmitted by the network access point is received at a remote terminal over the established communication link without providing responsive communications to the network access point from the remote terminal.
Abstract:
An audio playback device and method searches initiates a web search for images related to music or other audio files being played, downloads images from selected web pages returned by the search engine, and outputs one or more images from the selected web pages on a display to enhance the user's listening experience.