807 results about "Signal gain" patented technology

An apparatus and method for paging a user terminal (UT) using a satellite communications system having a gateway and one or more satellites, wherein each satellite produces a plurality of beams and each beam includes a plurality of channels. The method of the present invention includes the step of recalling a location of the UT, wherein the recalled location corresponds to a location of the UT at a time t1. In one embodiment this is accomplished by performing a lookup in a table that includes location information for user terminals at different points in time. The method also includes the step of determining an area, based on the recalled location, within which the UT is assumed to be located at a time t2, where time t2 is later in time than time t1. The next step is to determine a time t3, where t3 is equal to or later in time than time t2, when the following two criteria are satisfied. First a satellite of the one or more satellites has an elevation angle between theta1 and theta2. Second, all locations within the area are located within a footprint of the satellite (that has an elevation angle between theta1 and theta2). The elevation angles theta1 and theta2 can be determined from the perspective of the recalled location. Alternatively, the elevation angle can be determined from the perspective of all locations within the area. This ensures that the UT is in the "sweet spot" of the satellite (where the gain of signals sent from the satellite are highest) when the UT is paged. A page is then sent from the gateway to the UT on a channel of a beam of the satellite at time t3. The page can be sent on a channel of every beam of a plurality of beams that make up the footprint of the satellite at time t3. Alternatively, the page can be sent on a channel of selected beams of the footprint. By waiting until the UT is within the "sweet spot" to page the UT, less power can be used by the satellite. In addition, this type of operation allows the UT to use an antenna that has a substantial gain only when the UT is within the "sweet spot". This allows the use of satellite power to be reduced further.

A gain compensator compensates for the gain variation of a varactor-tuned voltage tuned oscillator (VCO) in a phase lock loop (PLL). The VCO includes a parallel LC circuit having multiple fixed capacitors that can be switched-in or switched-out of the LC circuit according to a capacitor control signal to perform band-select tuning of the VCO. The gain compensator compensates for the variable VCO gain by generating a charge pump reference current that is based on the same capacitor control signal that controls the fixed capacitors in the LC circuit. The gain compensator generates the charge pump reference current by replicating a reference scale current using unit current sources. The number of times the reference scale current is replicated is based on the fixed capacitance that is switched-in to the LC circuit and therefore the frequency band of the PLL. The reference scale current is generated based on a PLL control that specifics certain PLL characteristics such as reference frequency, loop bandwidth, and loop damping. Therefore, the reference pump current can be efficiently optimized for changing PLL operating conditions, in addition to compensating for variable VCO gain.

The present technique relates to a sound processing apparatus, a method, and a program capable of alleviating degradation of the quality of sound in a case where the gain of a sound signal is amplified.When equalizer processing for adjusting the gain of each frequency band of an input signal on the basis of a gain setting value is performed, an input signal is attenuated by an input attenuation amount derived from the gain setting value, and the equalizer processing is performed on the input signal attenuated. The amount of amplification of the gain of the input signal in the equalizer processing is estimated on the basis of the gain setting value and a weight coefficient of each frequency band derived from a generally-available music signal prepared in advance, and a difference of the estimation value and the input attenuation amount is calculated as a gain correction amount. Further, nonlinear amplification processing is performed on the input signal so as to actually amplify the input signal, which has been subjected to the equalizer processing, by a gain correction amount, and an output signal is obtained. The present technique can be applied to a sound processing apparatus.

A mixer for direct conversion transmitters and receivers using four phase-shifted local oscillation signals that are orthogonal each other to control a plurality of switches for outputting signals that are orthogonal each other. Two output signals that are orthogonal to each other do not mutually interfere and have a predetermined small signal gain. Further, a mixer may include four or eight switches controlled by four phase-shifted local oscillation signals that are orthogonal each other for outputting signals that are orthogonal to each other on an I-Q plot. The signals outputted from the switches controlled by four phase-shifted local oscillation signals remove I-Q mismatch and a DC component, and improve IP2 characteristics.

A mixer for direct conversion transmitters and receivers using four phase-shifted local oscillation signals that are orthogonal each other to control a plurality of switches for outputting signals that are orthogonal each other. Two output signals that are orthogonal to each other do not mutually interfere and have a predetermined small signal gain. Further, a mixer may include four or eight switches controlled by four phase-shifted local oscillation signals that are orthogonal each other for outputting signals that are orthogonal to each other on an I-Q plot. The signals outputted from the switches controlled by four phase-shifted local oscillation signals remove I-Q mismatch and a DC component, and improve IP2 characteristics.

An optical receiver includes a photodetector for detecting incoming optical data signals and an amplifier for providing signal gain and current to voltage conversion. The detection signal generated by the photodetector may include a distortion component caused by an operating characteristic of the photodetector. A signal compensating circuit may reconstruct the received optical data signal by effectively canceling the distortion component. For this purpose, the signal compensating circuit may include a decision feedback equalizer implemented using at least one feedback filter matched to the operating characteristic of the photodetector causing the signal distortion so as to reproduce the distortion component for cancellation. Use of a control module may also configure the optical receiver in real time to account for other operating and environmental conditions of the optical receiver. Data rates in excess of 5 Gbps may be realized in monolithic CMOS photodetectors when the signal compensating circuit is properly matched.

A predistorter is disclosed that predistorts an input signal based on one or more static coefficients that are representative of a non-linear distortion characteristic of an amplifier. The input signal is also processed based on a non-linear gain parameter that reduces an error metric between the input signal and a feedback signal. The nonlinear gain parameter adapts an amount of nonlinearity introduced by the predistorter. The non-linear gain adaptation is performed, for example, when the input voltage is above a threshold input voltage. The input signal can be processed by multiplying the input signal by the non-linear gain parameter followed by table-coefficient processing, or by both multiplying the input by the non-linear gain parameter followed by dividing the table-coefficient processed output signal by the same non-linear gain parameter. The input signal can also be processed based on a feedback gain parameter that compensates for a small-signal gain of the feedback loop. The feedback gain parameter attempts to maintain a small-signal gain of approximately unity.

An apparatus for extracting an ambient signal from an input audio signal comprises a gain-value determinator configured to determine a sequence of time-varying ambient signal gain values for a given frequency band of the time-frequency distribution of the input audio signal in dependence on the input audio signal. The apparatus comprises a weighter configured to weight one of the sub-band signals representing the given frequency band of the time-frequency-domain representation with the time-varying gain values, to obtain a weighted sub-band signal. The gain-value determinator is configured to obtain one or more quantitative feature-values describing one or more features of the input audio signal and to provide the gain-value as a function of the one or more quantitative feature values such that the gain values are quantitatively dependent on the quantitative values. The gain value determinator is configured to determine the gain values such that ambience components are emphasized over non-ambience components in the weighted sub-band signal.

A CDMA subscriber unit includes an antenna system having multiple antennas and delay units for receiving a transmitted signal and outputting a combined signal having a known distortion imparted by the antenna system. The combined signal is in turn processed by a modem, which compensates for the known distortion in a manner which provides improved signal gain. The improved signal gain permits a reduction in transmit power and, accordingly, increased capacity of the base station. Where the antenna system is to be remotely located from related signal processing equipment, separate units for the RF receiver / transmitter and the other signal processing equipment are provided so that the RF receiver / transmitter may also be remotely located along with the antenna system.

A wideband splitter includes a core amplifier for receiving a single pair of differential input signals and providing first and second pairs of differential output signals. The first pair of differential output signals and the second pair of differential outputs have substantially identical characteristics. A signal gain is implemented between the received single pair of differential input signals and the first and second pair of differential output signals. The signal gain is substantially constant across the frequency bandwidth of the core amplifier. A bandwidth peaking network is coupled to the core amplifier and includes (a) a first coil and a first resistor connected in series and (b) a second coil and a second resistor connected in series. The bandwidth peaking network is configured to increase the frequency bandwidth of the core amplifier.