Abstract: A method for controlling a multimedia system on an automobile that includes at least one module for executing a multimedia function, having at least one operation state controlled by an action of the user on an interface. The multimedia system includes a prestart state in which at least one prescribed task of the module that does not require any action by the user is initiated, a detection mechanism monitors the occurrence of a vehicle opening or unlocking event, the module is temporarily set in the prestart state following the detection of the event, the module being capable, when in the prestart state, of being switched to the operation state when the user acts on the interface.

Abstract: A system, such as a transceiver, for controlling an adjustable power level includes first and second power detectors, a network of attenuators, a compensator, a comparator, and a controller. The first power detector measures the power of a signal. The network of attenuators receives the signal and generates an attenuated signal. The compensator receives the attenuated signal and generates a compensated signal. The second power detector measures the power of the compensated signal. The comparator receives the respective outputs from the first and second power detectors and generates a first error signal. The controller enables the fixed attenuation, correspondingly adjusts the variable attenuation, receives a second error signal, and provides a control signal to the network of attenuators to nullify an attenuation mismatch introduced between the fixed attenuation and the variable attenuation. A corresponding method for controlling an adjustable power level is also disclosed.

Abstract: A programmable controller and software that monitors periods an RF transmitter is active and a output power level during those periods of activity. These two values are multiplied together and accumulated over time to provide a value for the RF emissions for some period. A limit is set for the RF emissions for any period and if the RF emissions exceeds (or is expected to exceed given the current rate) the set limit, the system limits the subsequent emissions to not exceed the set limit. This reduction in emissions rate come at the cost of a small performance reduction.

Abstract: Systems and methods for virtualizing the peripherals in a wireless device to enable remote management via removable portable media with processing capability are described. One aspect may include a system for virtualizing a peripheral device of a wireless device from a media device, the system comprising a media device, including a first memory; a processor coupled to said first memory; and a virtualization device controller interface remote layer adapted to run on said processor and first memory, wherein said virtualization device controller interface remote layer is adapted to communicate with a peripheral device of the wireless device.

Abstract: A linearizer for a non-linear transmitter includes a tap delay line that provides samples of an input signal at selected times. At least one Volterra tap is coupled to the tape delay line. The Volterra tap includes a lookup table representation of a polynomial. An adaptive controller is coupled to the Volterra tap for modifying values in the lookup table.

Abstract: Transmitter circuits for generating baseband signals having low receiver-band noise are disclosed. In one embodiment, the transmitter circuit comprises an active filtering-and-amplifying component comprising a first input configured to receive a first input signal, and a first output configured to output a first output signal. The transmitter circuit further comprises a passive filtering component comprising a second input connected to the first output and configured to receive the first output signal, a passive pole arrangement comprising a number of switchable resistance elements and a capacitance element connected across the plurality of switchable resistance elements, and a second output configured to output a second output signal having reduced noise as compared to the first output signal. The transmitter still further comprises a number of feedback loops connecting the passive filtering component to the first input.

Abstract: A method for an antenna system including a transmitting phase array antenna including a transmitting antenna subarray including a number of antenna elements transmitting on a first frequency and a receiving phase array antenna including a receiving antenna subarray including a number of antenna elements. The transmitting antenna subarray antenna is positioned at a distance relative the receiving antenna subarray antenna and the coupling between two antenna subarrays are decided and used for controlling the transmitting subarray antenna to transmit in such a way that there will be nulling of the energy in the receiving antenna subarray antenna with respect to the transmitting antenna subarray.

Abstract: A power amplifier power controller in the power amplifier system monitors various operating conditions of the power amplifier, and controls the output transmit power of the power amplifier by coordinated control of both the input drive level to the power amplifier and the gain of the power amplifier. The power amplifier power controller controls the input drive level to the power amplifier so that the input drive level does not change substantially while adjusting the gain of the power amplifier to maximize the transmit power. The power amplifier power controller may also adjust the input drive level by some portion of the overall change required to the power of the power amplifier, while adjusting the gain of the power amplifier by the remaining portion of such overall change.

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: Embodiments for at methods, apparatus and systems for operating a voltage regulator are disclosed. One method includes generating, by a switching controller, a switching voltage through controlled closing and opening of a series switch element and a shunt switch element. Further, the method includes generating, by a switchable output filter, a regulated output voltage by filtering the switching voltage, wherein the switchable output filter comprises a plurality of capacitors that are selectively included within the switchable output filter.

Abstract: Techniques for performing power control of multiple channels sent using multiple radio technologies are described. The transmit power of a reference channel, sent using a first radio technology (e.g., CDMA), is adjusted to achieve a target level of performance (e.g., a target erasure rate) for the reference channel. The transmit power of a data channel, sent using a second radio technology (e.g., OFDMA), is adjusted based on the transmit power of the reference channel. In one power control scheme, a reference power spectral density (PSD) level is determined based on the transmit power of the reference channel. A transmit PSD delta for the data channel is adjusted based on interference estimates. A transmit PSD of the data channel is determined based on the reference PSD level and the transmit PSD delta. The transmit power of the data channel is then set to achieve the transmit PSD for the data channel.

Abstract: A satellite communication system includes a satellite earth station operably coupled to a data network, and a plurality of satellite modems, each satellite modem of the plurality of satellite modems communicating in an upstream and downstream data communication mode with the satellite earth station via at least one servicing satellite.

Abstract: A receiver/transmitter and related receiving/method capable of simultaneously receiving/transmitting discontinuous frequency band signal components of an input/output signal are provided. Phase swapping on in-phase/quadrature-phase local oscillation differential signals is applied to frequency down-conversion of the input signal or frequency up-conversion of a baseband signal to be outputted to radio domain, and thereby achieve simultaneously receiving discontinuous frequency bands of the input signal and simultaneously sending different baseband signal components on discontinuous frequency bands of the output signal.

Abstract: Polyphase sequence generation is provided for sequences having good aperiodic correlation properties. The sequences can allow lengths not attainable by other types of sequences (such as Frank sequences) and can yield increase merit factors and more desirable peak-to-side-peak ratios (and therefore decreased sidelobe energy) than other sequences (such as Chu sequences). Perfect root-of-unity sequences of lengths up to 32, achieving the minimum phase alphabets and the maximum merit factors and/or peak-to-side-peak ratios, are searched, and the results are tabulated. Comparing the merit factors and peak-to-side-peak ratios of the best search results to other sequences, a common construction pattern of the improved sequences of length 2m2 are obtained. The improved sequences can be utilized in a variety of configurations, including spread spectrum communication, radar, channel estimation, system identification, and/or the like.

Abstract: A receiver operatively coupled to an antenna structure capable of receiving a first plurality of RF signals is disclosed herein. The receiver includes an RF processing network operative to perform weighting and combining operations within the RF domain using the first plurality of RF signals so as to produce a second plurality of RF signals. Also provided is a downconverter configured to downconvert the second plurality of RF signals into a second plurality of down-converted signals. In alternate implementations certain of the weighting and combining operations are performed at baseband and the remainder effected within the RF domain. A transmitter of corresponding architecture is also disclosed.

Abstract: According to one embodiment, a digital-to-analog converter includes a plurality of cells. Each cell includes a current source and a differential switch. The current source includes a first transistor arranged in a first region and connected to either a power source or a ground, a second transistor arranged in a second region which is different from the first region and connected directly or indirectly with the first transistor in a cascode configuration, and a metallic interconnect connecting the first region and the second region electrically. The differential switch includes a pair of transistors, each connected to the second transistor and arranged in the second region.

Abstract: A transceiver includes a transmitter circuit, a receiver circuit, and the loopback switch. The transmitter circuit performs a digital-to-analog conversion (DAC) operation on a calibration code without a transmission digital signal in a calibration mode to generate a calibration signal. The transmitter circuit up-converts the calibration signal and generates a transmission signal. The receiver circuit down-converts the transmission signal in the calibration mode and generates a receiving digital signal. The loopback switch electrically connects an output terminal of the transmitter circuit and an input terminal of the receiver circuit in the calibration mode. Thus, the transceiver may stably reduce a carrier leakage irrespective of processes, voltages, and temperatures.

Abstract: A communication system for accessing media items via a display device. A receiver is coupled to the display device and a transmitter is coupled to a computer system. Media items stored locally on the computer system and/or remotely on a remote server may be wirelessly transferred from the transmitter to the receiver for display on the display device. In addition, the transmitter and the receiver may be pre-paired prior to delivery to the user, allowing for the network to be configured without any user input. Advantageously, embodiments provide a user with the ability to conveniently view content stored on a computer or a web server without the user having to perform any wireless network setup procedures.

Abstract: A programmable-current transmit continuous-time filter (TX-CTF) system can be included in a radio frequency (RF) transmitter. The input of the TX-CTF can receive a baseband transmission signal, and the output of the TX-CTF can be provided to an upconversion mixer for conversion to RF for transmission. The TX-CTF includes amplifier circuitry and passive circuitry that together define the filter parameters. The TX-CTF further includes programmable current circuitry that provides a programmable bias current to the amplifier circuitry. The TX-CTF system also includes control logic that receives one or more transmitter control signals and, in response, generates signals that control the bias current provided to the TX-CTF.

Abstract: Systems and methods for measuring transmitter and/or receiver I/Q impairments are disclosed, including iterative methods for measuring transmitter I/Q impairments using shared local oscillators, iterative methods for measuring transmitter I/Q impairments using intentionally-offset local oscillators, and methods for measuring receiver I/Q impairments. Also disclosed are methods for computing I/Q impairments from a sampled complex signal, methods for computing DC properties of a signal path between the transmitter and receiver, and methods for transforming I/Q impairments through a linear system.

Abstract: In various embodiments of the present disclosure, there is provided a receiver for body channel communication. The receiver includes an electrode configured to receive an incoming signal transmitted as a multi-level transmission signal from a transmitter through a body channel, a differentiator configured to obtain a time derivative of the incoming signal indicating a plurality of data transitions, and an analog to digital converter configured to generate a multi-level output signal representing the multi-level transmission signal based on the plurality of data transitions. A corresponding method of controlling a receiver for body channel communications is provided.

Abstract: A non-reciprocal circuit element includes a ferrite, a first central electrode and a second central electrode arranged on the ferrite so as to cross each other in an insulated state, and a permanent magnet that applies a DC magnetic field to a portion where the first and second central electrodes cross each other. One end of the first central electrode defines an input port, and the other end thereof defines an output port. One end of the second central electrode defines the input port, and the other end thereof defines a ground port. A resistance element and a capacitance element, which are connected in parallel with each other, are connected in series with and between the input port and the output port. Input impedance is lowered by making inductance of the second central electrode relatively large.

Abstract: An integrated circuit comprises a digitally-controlled power generation stage (DPA) for converting an input signal to a radio frequency (RF) carrier, the DPA comprising a plurality of selectable switching devices capable of adjusting an envelope of the RF carrier; and a pulse width modulator (PWM) generator arranged to generate a PWM control signal and operably coupleable to the plurality of selectable switching devices of the DPA. The PWM generator inputs the PWM control signal to a subset of the plurality of the selectable switching devices such that a PWM signal adjusts the envelope RF carrier output from the DPA.

Abstract: In accordance with an embodiment, a system has an audio amplifier configured to be coupled to a speaker coil port via a parallel resonant circuit, and a radio frequency (RF) amplifier configured to transmit a RF signal at a first RF transmission frequency. The speaker coil port is configured to be coupled to a speaker coil, and the parallel resonant circuit has a resonance frequency of about the first RF transmission frequency.

Abstract: A transmitter (20) includes a peak reduction section (30), a predistorter (98), and an amplifying section (102) biased by a variable bias signal generator (118). The peak reduction section (30) is controlled by a signal magnitude threshold (36) that defines maximum magnitudes for local peaks (32) of a reduced-peak communication signal (38). The bias signal generator (118) is controlled by a bias control signal (110). Both the signal magnitude threshold (36) and the bias control signal (110) are derived from a common reduced bandwidth (50) peak-tracking signal (42). The peak-tracking signal (42) is derived from an inflated-peak communication signal (26). The predistorter (98) applies distortion to the reduced-peak communication signal (38) that is configured, at least in part, by the bias control signal (110).

Abstract: Cellular processors are cascaded to provide different configurations, which result in higher-capacity base stations, increased numbers of simultaneous users over one frequency band, and/or aggregation of several carriers while still using only one radio frequency (RF) chipset. The processors are aligned in both time and frequency, with each processor having a data port that allows data exchange with the other processors. The data alignment and exchange allow the processors, in the aggregate, to act as a single unit, resulting in a scalable architecture that can accommodate different system configurations.

Abstract: The present disclosure relates to RF front-end (RFFE) circuitry that includes multiple RFFE circuits, each of which may be provided by a separate integrated circuit (IC), front-end module, or both. As such, the RFFE circuits may be connected to one another using an RFFE serial communications bus. Further, one or more of the RFFE circuits may need an accurate clock source for analog-to-digital conversion (ADC), digital-to-analog conversion (DAC), calibration, sensor measurements, or the like. Instead of including an integral clock source circuit or receiving a separate external clock signal, an RFFE circuit may extract clock information from the RFFE serial communications bus to provide one or more clock signal. The clock information may be associated with one or more serial communications command via the RFFE serial communications bus.

Abstract: A multi-mode driver amplifier with tunable load matching is disclosed. In an exemplary design, an apparatus includes a multi-mode driver amplifier and a tunable impedance matching circuit. The driver amplifier amplifies an input radio frequency (RF) signal and provides an amplified RF signal. The tunable impedance matching circuit matches an output impedance of the driver amplifier. The apparatus may include a main transmit path and a bypass transmit path. The bypass transmit path may include the driver amplifier and the tunable impedance matching circuit and no power amplifier. The main transmit path may include a second driver amplifier and a power amplifier. The main transmit path may be selected for transmit power levels higher than a threshold level, and the bypass transmit path may be selected for transmit power levels lower than the threshold level.

Abstract: Apparatus and methods for QAM modulation are disclosed using dual polar modulation. QAM modulation of a signal is accomplished by translating a QAM signal into two phasors having the same or constant amplitude and then phase shifting one of the phasor by 180 degrees for a differential load. The phasors are then polar modulated such that, when differentially combined in the load through summation or superposition, a QAM modulated symbol results. The use of constant amplitude phasors when power amplified for transmission of QAM modulated signals allows amplifiers to be operated in a saturation mode with greater efficiency than conventional amplifiers used in QAM modulation, which operate in a less efficient linear mode to effect amplitude modulation. Additionally, differential combining of the phasors affords relaxation of the turns of a transformer used in amplifying the phasors.

Abstract: A distortion compensation device includes a distortion compensator that predistorts an input signal based on delay signals and distortion compensation coefficients corresponding to the respective delay signals obtained by applying different amounts of delay to the input signal, a calculator that calculates an error signal based on the predistorted input signal and an output signal from an amplifier that amplifies the predistorted input signal, a calculator that calculates prospective distortion compensation coefficients for updating the distortion compensation coefficients, based on the error signal, a saturation processor that performs saturation processing for bringing, when the prospective distortion compensation coefficients do not fall into a preset range, the prospective distortion compensation coefficients into the preset range, and a controller that controls the updating of the distortion compensation coefficients based on pieces of coefficient saturation information indicating whether the saturation

Abstract: A peak suppressing apparatus includes a pre-emphasis section that performs a pre-emphasis process on a signal, which is to be wirelessly transmitted and a peak of which is to be suppressed, the pre-emphasis process emphasizing a given frequency range component of the signal, a clipping section that limits, to a given threshold value, an amplitude of the signal that has been subjected to the pre-emphasis process, a de-emphasis section that performs a de-emphasis process on the signal, whose amplitude has been limited, the de-emphasis process suppressing the given frequency range component of the signal, and a frequency converter that converts, to allow wireless transmission, a frequency of the signal that has been subjected to the de-emphasis process.

Abstract: A fractional rate converting filter in a wireless transceiver comprising a delay line, multiplier circuit, adder circuit, and selector. The delay line receives a digital input signal at a first sample rate and has delay blocks each providing an output and receiving samples gated at a plurality of clock cycles of an integer sub-multiple frequency of a clock. The outputs are multiplied by corresponding filter tap coefficients. Each filter tap coefficient is spaced by a first integer Y. The adder circuit receives and sums the tap outputs to provide an output signal. The selector iteratively shifts the coefficients by a second integer Z. The output of each delay block is multiplied by corresponding shifted filter tap coefficients. The delay blocks are inhibited from receiving another input sample during the plurality of clock cycles. The output signal has a second sample rate at the integer sub-multiple frequency of the clock.

Abstract: A signal separating unit separates an input signal into a first branch signal and a second branch signal in such a manner that, as the amplitude of the input signal decreases, the amplitude of the first branch signal and the second branch signal decreases and the difference between a phase of the first branch signal and a phase of the second branch signal increases and, as the amplitude of the input signal increases, the amplitude of the first branch signal and the second branch signal increases and the difference between the phase of the first branch signal and the phase of the second branch signal decreases. An amplifier amplifies the first branch signal. Another amplifier amplifies the second branch signal. A combining unit combines signals that are output from the amplifiers together, thereby generating an output signal.

Abstract: A mobile terminal and controlling method thereof are disclosed, by which a scheduling function of giving a processing order to each of a plurality of tasks is supported. The present invention includes a memory including an operating system having a scheduler configured to perform a second scheduling function on a plurality of tasks, each having a processing order first-scheduled in accordance with a first reference and a processor performing an operation related to the operating system, the processor processing a plurality of the tasks. Moreover, if a first task among a plurality of the first-scheduled tasks meets a second reference, the scheduler performs the second scheduling function by changing the processing orders to enable the first task to be preferentially processed.

Abstract: Systems and methods for compensating for non-linearity of a non-linear subsystem using predistortion are disclosed. In one embodiment, a system includes a non-linear subsystem and a predistorter configured to effect predistortion of an input signal of the non-linear subsystem such that the predistortion compensates for a non-linear characteristic of the non-linear subsystem. The system also includes an adaptor that adaptively configures the predistorter based on a feedback signal that is representative of an output signal of the non-linear subsystem and an input signal that is representative of the input signal of the non-linear subsystem. The adaptor generally models the non-linear subsystem as a concatenation of a non-linear model that corresponds to the non-linear characteristic of the non-linear subsystem and a linear model that corresponds to a known linear characteristic of the non-linear subsystem.

Abstract: A transmitter module for unidirectional communication with a receiver module and a method using the aforementioned. The transmitter module includes a carrier detection portion, a source processing portion coupled to the carrier detection portion and a source transmission portion coupled to the source processing portion. The source processing portion can receive and process an information signal to produce a processed information signal in a manner such that an appropriate carrier signal is modulated with the information signal. The appropriate carrier signal can be based on the detection signals communicated from the carrier detection portion. The source processing portion can further process the information signal in a manner such that the processed information signal is associable with at least one of a unique code and an indication signal. The indication signal is associable with absence of communication of the at least one communication signal in a communication medium.

Abstract: In one embodiment, receiving an Ethernet signal over a channel, the Ethernet signal comprising a preamble frame, an idle frame, and a data frame, the preamble frame comprising one or more preamble codes; synchronizing to the Ethernet signal based on the preamble frame; replicating the one or more preamble codes; and training a decision feedback equalizer (DFE) based on the one or more replicated codes, the training enabling the DFE to use decision values at the DFE output to track channel variations.

Abstract: An apparatus and method for supplying power to circuits of an integrated circuit (IC) from the wasted power in low-swing high-speed differential line drivers used in the IC, is disclosed. In a high speed line driver the load resistors of the driver are connected to a power supply, either the local power supply or the receiver power supply. DC power for the driver is supplied through these resistors. A large portion of this power, supplied from the power supply is wasted in the DC set-up circuit of the differential line driver. It is proposed to use this wasted power to power selected circuits of an IC. The use of this wasted power from the drivers for powering the circuits reduces the overall power dissipation of the system.

Abstract: A wireless communication device retrieves a continuous stream of data by receiving a request for retrieval of content from a remote server, retrieving data of the requested content over a first radio access technology (RAT) interface and connection, and determining if the data retrieved meets a content playback threshold. When the retrieved data does not to meet the content playback threshold, the device activates a second RAT interface for retrieval of data of the requested content over a second RAT connection. The first and second RAT interfaces simultaneously retrieve part of the requested content during a multipath time period, which part is divided into at least a first portion for retrieval over the first RAT connection and a second portion for retrieval over the second RAT connection and which first and second portions are selected such that their retrieval is estimated to meet the content playback threshold.

Abstract: A communication device includes memory, an input interface, a processing module, and a transmitter. The processing module receives a digital signal from the input interface, wherein the digital signal includes a desired digital signal component and an undesired digital signal component. The processing module identifies one of a plurality of codebooks based on the undesired digital signal component. The processing module then identifies a codebook entry from the one of the plurality of codebooks based on the desired digital signal component to produce a selected codebook entry. The processing module then generates a coded signal based on the selected codebook entry, wherein the coded signal includes a substantially unattenuated representation of the desired digital signal component and an attenuated representation of the undesired digital signal component. The transmitter converts the coded signal into an outbound signal in accordance with a signaling protocol and transmits it.

Abstract: An efficient coding and modulation system for transmission of digital data over plastic optical fibers is disclosed. The digital signal is coded by a three-level coset coding. The spectral efficiency of the system is configurable by selecting the number of bits to be processed in each of the levels. The first level applies to the digital data a binary BCH coding and performs coset partitioning by constellation mapping and lattice transformations. Similarly, second level applies another binary BCH coding, which may be performed selectably in accordance with the desired configuration by two BCH codes with substantially the same coding rate, operating on codewords of different sizes. The third level is uncoded. The second and third levels undergo mapping and lattice transformation. After an addition of the levels, a second-stage lattice transformation is performed to obtain a zero-mean constellation. The symbols output from such three-level coset coder are then further modulated.

Abstract: Various embodiments provide for systems and methods for signal conversion of one modulated signal to another modulated signal using demodulation and then re-modulation. According to some embodiments, a signal receiving system may comprise an I/Q demodulator that demodulates a first modulated signal to an in-phase (“I”) signal and a quadrature (“Q”) signal, an I/Q signal adjustor that adaptively adjusts the Q signal to increase the signal-to-noise ratio (SNR) of a transitory signal that is based on a second modulated signal, and an I/Q modulator that modulates the I signal and the adjusted Q signal to the second modulated signal. To increase the SNR, the Q signal may be adjusted based on a calculated error determined for the transitory signal during demodulation by a demodulator downstream from the I/Q modulator.

Abstract: An embodiment includes an apparatus for wireless communications in a drilling operations environment. In an embodiment, the apparatus includes an instrument hub that is inline with drill pipe of a drill string. The instrument hub includes a sensor to receive downhole communications from downhole. The instrument hub also includes a transmitter to wireless transmit data representative of the downhole communications to a data processor unit.

Abstract: Systems, methods, and devices for wireless communication. In one aspect, an apparatus for wireless communication is provided. The apparatus includes a receiver configured to receive a wireless signal comprising a packet. At least a portion of the wireless signal is configured to be received over a bandwidth lower than or equal to 1.25 MHz. The packet is formed from at least one orthogonal frequency-division multiplexing (OFDM) symbol comprising thirty-two tones. The thirty-two tones correspond to frequency subcarriers within the bandwidth. The thirty-two tones of the at least one OFDM symbol are allocated as: twenty-four data tones, two pilot tones, five guard tones, and one direct current (DC) tone. The apparatus includes a processor configured to evaluate the wireless signal. The processor includes a transform module configured to convert the at least one OFDM symbol into a frequency domain signal using a thirty-two point mode.

Abstract: An electronic device includes an adjustable filter with a first filter element, and a second filter element coupled to the first filter element. The second filter element includes a field effect transistor (FET) including a source terminal, a drain terminal, and a gate terminal. The source terminal and the gate terminal are coupled to a reference voltage. A control circuit is coupled to the drain terminal and is configured to apply a control voltage thereto to vary a capacitance between the source and drain terminals to adjust the adjustable filter.

Abstract: Wideband-Code Division Multiple Access (W-CDMA) transmit architecture. A baseband digital processing module operates cooperatively with an analog signal processing module to effectuate highly adjustable and highly accurate gain adjustment in accordance with transmitter processing within a communication device. The gain adjustment and/or gain control is partitioned between the digital and analog domains by employing two cooperatively operating digital and analog modules, respectively. Gain adjustment in the analog domain is performed in a relatively more coarse fashion that in the digital domain. If desired, gain adjustment in each of the analog and digital domains is performed across a range of discrete steps. The discrete steps in the analog domain are larger than the discrete steps in the digital domain. Also, the discrete steps in the digital domain may be interposed between two successive discrete steps in the analog domain.

Abstract: Disclosed are a method and an apparatus for transmitting and receiving broadcast data in a digital broadcasting system. The method for transmitting and receiving broadcast data in a digital broadcasting system includes receiving the main data encoded with symbols having a plurality of levels; deciding whether levels of main data symbols encoded with symbols having the plurality of levels belong to a first group; and mapping the main data symbols to extended levels by using modulation values of the additional data if it is decided that the levels of the main data symbols belong to the first group.

Abstract: An adjustable filter is responsive to a control signal to change a frequency response of the adjustable filter based on frequency spectrum information. The control signal may shift a center of the pass band from a first center frequency to a second center frequency and/or change a pass band bandwidth from a first bandwidth to a second bandwidth. In one example, the frequency spectrum information includes a status of an internal secondary radio. The frequency spectrum information may also indicate a region of operation where the frequency response is selected in accordance with the region.

Abstract: A multipath circuit is described that has multiple signal paths and various common components used for normal operation. Each of the multiple signal paths also has multiple circuit blocks defining the functionality of the signal path. A shared access path is provided through the third winding of a three-way transformer for each signal path. Multiple switches are provided in the multipath circuit that couple to the third winding in each of the multiple signal paths. The switches are also coupled to the various common components. Selected ones of these switches may be closed to provide a shared access path between a common component and one of the signal paths or between a common components and one of the circuit blocks in one of the signal paths.

Abstract: Method and apparatus for sensing the envelope of high level multi frequency band RF signals in power amplifiers. For each frequency band, an RF transistor, such as a FET or a bipolar transistor is operated essentially at a non-linear operating point (e.g., in Class B, AB or C) at the frequency band. The RF transistor is fed by a DC power supply trough an RF filter and terminated by a dummy load that is tuned to the frequency band so as to terminate the RF components in the output signal of the RF transistor. An RF signal of the frequency band is fed into the input of the RF transistors and an output signal representing the envelope is obtained from the fluctuating current drawn from the DC power supply by the RF transistor, during the time period when the RF signal is applied to the input.