Abstract: Receiver network for receiving a first filtered modulated transmitted signal in a first RF band and a second modulated transmitted signal in a second RF band and for providing received signals to one or more demodulators. A demodulator and baseband filter for demodulating and filtering the first filtered modulated received signal and for providing filtered demodulated baseband signal by a baseband filter mismatched to the filter of the first filtered modulated transmitted signal and demodulating the second modulated signal providing a demodulated baseband signal and a selector for selecting either the first or the second demodulated baseband signal.

Abstract: The following process is eliminated to reduce the processing volume: calculating the amount of phase rotation from a reference signal point stored in the device, and carrying out further rotation so that a signal point is obtained that corresponds to the signal point obtained as a result of calculating the amount of phase rotation by using the signal point having an established timing as a reference signal point.

Abstract: A system and method for controlling modulation. The system includes a plurality of modulators and a transmitting unit. The plurality of modulators decodes data from a data signal and also encodes the data into a clock signal. The transmitting unit transmits the encoded clock signal. According to the system and method disclosed herein, the present invention provides optimized coding efficiency while minimizing overall power consumption.

Abstract: Transmitters, receivers and associated methods are disclosed for providing phase and amplitude modulation in a carrier-less communication system (e.g., an ultra-wide band communication system). An approximate quadrature signal is provided by delaying the in-phase signal by an amount determined by various criteria, such as the bandwidths of the component signals, minimizing the mean square error between an approximate quadrature signal and the true quadrature signal, and minimizing the auto-correlation function of the in-phase signal.

Abstract: A calibration device for a phase locked loop arranged to generate an output frequency based upon a first frequency range of an input signal applied to a first input and a second frequency range of the input signal applied to a second input, the calibration phase locked loop synthesizer device comprising an estimator arranged to use a two dimensional estimation algorithm with a signal value indicative of a mismatch between the first input path and the second input path to determine an estimate of the mismatch to allow matching of the first input path and the second input path.

Abstract: A broadband communications system uses modulation symbol transport over communications links to replace baseband or bandpass signal transport, thereby providing longer communication distances, lower communication link bandwidth, and greater signal quality. Subsequent to transporting the modulation symbols, the symbols are modulated and further transmitted over the RF transmission network.

Abstract: In one aspect, a data communication system includes a modulator, an integrated acoustic data coupler, and a demodulator. The modulator modulates a carrier signal having a frequency in an operating frequency range in response to an input data signal and provides the modulated carrier signal at a modulator output. The integrated acoustic data coupler includes an acoustically resonant structure that has one or more acoustic resonant frequencies in the operating frequency range. The acoustically resonant structure includes a first thin film electro-acoustic transducer electrically coupled to the modulator output, a second thin film electro-acoustic transducer, and a substrate. The substrate supports, acoustically couples, and provides an electrical isolation barrier between the first and second thin film electro-acoustic transducers.

Abstract: The present invention provides a digital (computational) branch calibrator which uses a feedback signal sensed from an RF transmit signal path following the combining stage of LINC circuitry of a transmitter to compensate for gain and phase imbalances occurring between branch fragment signals leading to the combiner. The calibrator feeds a quiet (zero) base band signal through the transmit path during the calibration sequence (i.e. a period when data is not transmitted) and adjusts the phase and gain of the phasor fragment signals input thereto by driving the sensed output power to zero. The calibration is performed by alternating phase and gain adjustments with predetermined (programmable) and multiple update parameters stages (speeds). A baseband modulation is preferably used to distinguish false leakage (e.g. due to local oscillator, LO, feed through and DC offset in the base band Tx) from imbalance leakage.

Abstract: The present invention is related to methods and apparatus that compensate for quadrature impairments of an analog quadrature modulator and/or demodulator over a relatively wide signal bandwidth. One embodiment pre-distorts baseband signals in a quadrature modulator compensation signal processor (QMCSP) to negate the quadrature impairment of an analog quadrature modulator and corrects a received baseband signal in a quadrature demodulator compensation signal processor (QDCSP) to cancel the quadrature impairment of an analog quadrature demodulator. The QMCSP and the QDCSP contain adaptive digital filter correction structures that pre-compensate and post-compensate, respectively, for the quadrature impairments introduced by the analog quadrature modulator and the analog quadrature demodulator over a relatively wide bandwidth.

Abstract: A system communicates data and includes an encoder for encoding communications data with a forward error correction code. A data randomizer randomizes the communications data with a random bit sequence and a combining circuit combines the communications data with known symbols into frames. A modulator maps the communications data into minimum shift keying or Gaussian minimum shift keying (MSK or GMSK) symbols based on a specific mapping algorithm to form a communications signal having an MSK or GMSK waveform over which the communications data can be transmitted.

Abstract: Provided is a transmitter circuit capable of operating with low distortion and high efficiency even in a modulation method using wide modulation bandwidth. In the transmitter circuit, a signal generation section (11) generates an amplitude signal and an angle-modulated signal. Based on a predetermined characteristic, a compensating filter (12) wave-shaping-processes the amplitude signal. A regulator (14) outputs a signal in accordance with a magnitude of the signal which has been wave-shaping-processed by the compensating filter (12). An amplitude modulator section (15) amplitude-modulates the angle-modulated signal by using the signal outputted from the regulator (14). A characteristic of the compensating filter (12) is an inverse of a transfer characteristic between an input at the regulator (14) and an output at the amplitude modulator section (15).

Abstract: Methods and apparatus to encode message input symbols in accordance with an accumulate-repeat-accumulate code with repetition three or four are disclosed. Block circulant matrices are used. A first method and apparatus make use of the block-circulant structure of the parity check matrix. A second method and apparatus use block-circulant generator matrices.

Abstract: Embodiments of the present disclosure provide a transmitter, a receiver and methods of operating a transmitter and a receiver. In one embodiment, the transmitter includes an input padding module configured to provide padded bits having padding bits added to payload bits for one or more control channels, and a scrambling module configured to apply a masking sequence to one or more of the padded bits to generate scrambled bits. Additionally, the transmitter also includes an encoding module configured to perform forward error correction encoding and rate matching on the scrambled bits to obtain a required number of control channel output bits, and a transmit module configured to transmit the control channel output bits for one or more control channels.

Abstract: A method and apparatus are disclosed for combining digital sidebands with an FM analog signal for IBOC transmission by a single antenna. Specifically, a high power filter combiner for combining an FM analog and a digital signal of the same channel, or frequency, is disclosed. The combiner has two inputs that respectively receive an FM analog and a digital signal to be transmitted in the same FM channel. The combiner has mild tuned filters interposed between the inputs and the output which are tuned to pass the FM analog signal while reflecting the digital signal such that the passed FM analog signal and the reflected digital signal combine as IBOC, i.e., an FM analog signal with digital sideband signals. The combined IBOC signal is provided at an output of the combiner, capable for transmission through a single antenna.

Abstract: A method is provided which improves reliability of channel estimation in a digital communication system by reducing the ambiguity in the recognition of received symbols evaluated for the channel estimation. A first plurality of bits is mapped to a modulation state according to a given Gray mapping of binary numbers to modulation states and plurality of bits transmitted. The plurality of bits is re-transmitted at least once, with a sub-set of bits contained in the plurality of bits inverted, and mapped to further modulation states according to the same Gray mapping. The bits to be inverted are determined in a way that the number of different vector sum results obtainable, for all combinations of bit values within the first plurality of bits, by adding vectors representing complex values of the first and further modulation states in a complex plane, is lower than the number of different modulation states within the Gray mapping.

Abstract: The present invention is related to a method for data transmission between a transmitter station and a receiver station of a communication system, especially a wireless communication system, employing a transmission scheme based on the principle of receiver orientation, wherein for the generation of low energy transmit signals within the transmitter station expanded landings on multiple representatives of the complex plane are used and wherein each one of the expanded landing is arranged within an expanded domain of the complex plane. The present invention further relates to a transmitter station and a communication system.

Abstract: The present invention relates to the field of data transmission. The invention has application to amplifiers, the transmission of data modulated signals, filters and/or matching circuits connected between an amplifier and a load, radio transmitters, the transmission of data modulated radio signals, filters and/or matching circuits used between a transmitter's power amplifier and an antenna and the field of Radio Frequency Identification (RFID), such as in the transmission of data between a tag and an interrogator. The present invention enables the transmission of phase modulated signals, by adjusting a device's tuning to substantially match the instantaneous frequency of the phase modulated signal.

Abstract: A radio frequency power amplifier (RF PA) apparatus includes an RF PA and a waveform converter. The waveform converter is configured to receive a sinusoidal RF signal and generate a nonsinusoidal RF signal, which is used to drive an active device (e.g., a field effect transistor (FET) or bipolar junction transistor (BJT)) of the RF PA. The nonsinusoidal RF signal, which may comprise a square wave or a substantially-square wave signal, has signal characteristics that result in less leakage through the active device's input-output parasitic capacitance, compared to the leakage that would result if the sinusoidal RF signal was used to drive the active device. The leakage control methods and apparatus of the present invention may be advantageously employed in a variety of applications including, for example, RF polar transmitters.

Abstract: A polar modulator arrangement has a first and a second node to receive a digital signal with a first and a second component corresponding to a digital amplitude component and a digital phase component. A digital interpolation filter generates an interpolated first component by interpolating and filtering the first component. A polar modulated radio frequency signal is generated by a combination element as a function of the interpolated first component and the second component.

Abstract: Methods and apparatuses employing symmetrical phase-shift keying (SPSK) for data modulation and demodulation. Each symbol in a transmission signal carries n-bit information and is transmitted with one of 2n+1 directions. Half directions among the 2n+1 directions are regarded as default directions and the remaining are regarded as complementary directions. Each default direction has a corresponding complementary direction with a phase difference of ? and representing the same n-bit information as the default direction. The phase difference between any two successive symbols after modulation is less than or equal to ?/2.

Abstract: Systems, methods, and apparatus for reducing dynamic range requirements of a power amplifier in a wireless device are provided. An exemplary method may include modulating a symbol stream to generate a modulated waveform. The exemplary method may further include generating at least one pulse having a peak aligned with an anticipated position of a peak or a null corresponding to the modulated waveform, where the anticipated position of the a peak or the null corresponding to modulated waveform may be determined by detecting a transition in a phase or an amplitude of the modulated waveform.

Abstract: An amplitude component of a modulating signal is detected, band-divided by first and second frequency selecting circuits, and an amplitude component of a high-frequency band is down-converted by a first frequency conversion circuit. An amplitude component selected by the first frequency selecting circuit and an amplitude component selected by the first frequency conversion circuit are amplified by first and second operational amplifiers, and a signal amplified by the second operational amplifier is up-converted by a second frequency conversion circuit to be restored to the initial frequency band. Output amplitudes of the first operational amplifier and a second frequency converter are added up by an adder to be direct-current converted. The amplitudes after the direct-current conversion are band-divided by third and fourth frequency selecting circuits, respectively, feedback amounts thereof are adjusted, and then fed back to the first and second operational amplifiers.

Abstract: A method and apparatus for wirelessly transmitting data between two devices (101. 102) is provided herein. During data transmission, a data and a strobe signal are transmitted simultaneously on the I and Q-channels, respectively, of over-the-air interface. More particularly, QPSK modulation is utilized, with the strobe signal being transmitted via the I-channel, and the data signal being transmitted via the Q channel, (or vice versa). Additionally, illegal constellation transitions are utilized to signal the transmission of control information.

Abstract: The present invention relates to methods and apparatus for preventing power imbalance in a multiple input multiple output (MIMO) wireless precoding system. According to one aspect of the present invention, a codebook is constructed with a first subset of codewords that are constant modulus matrices, and a second subset of codewords that are non-constant modulus matrices. A mapping scheme is established between the first subset of codewords and the second subset of codewords. When a unit of user equipment feeds back a first codeword that is a non-constant modulus matrix, the Node-B may replace the first codewords with a second codeword that is selected from the first subset of codewords and that corresponds to the first codeword in accordance with the mapping scheme.

Abstract: An apparatus and method for full-diversity, full-rate space-time block coding in a transmitter using two Tx antennas are provided. An input symbol sequence is STBC-encoded in a predetermined method and transmitted through the two Tx antennas.

Abstract: A multimode-based phase modulating apparatus capable of reducing the degradation of modulation precision and suppressing the unnecessary power consumption. This apparatus has a switch for switching the modulation modes of a PLL circuit between a single-point modulation and a double-point modulation. In a case of a narrow modulation bandwidth, the switch is turned off to cease a second digital baseband signal, thereby causing the PLL circuit to perform the single-point modulation in which only a first digital baseband signal from a frequency division rate generating part is used for the modulation. Contrarily, in a case of a wide modulation bandwidth, the switch is turned on, thereby performing the double-point modulation using both the first digital baseband signal and the second digital baseband signal.

Abstract: A transmitter (106) for transmitting a signal, the signal comprising a plurality of signal values, the signal values being grouped to at least one signal value block. The transmitter comprises a pre-transformation unit (101) adapted to process each signal value block by a pre-transformation to produce a block of modulation symbols, wherein the pre-transformation comprises a phase rotation of the signal block values, which corresponds to the multiplication of the signal value block with a phase rotation matrix. The transmitter also comprises a modulation unit (102) adapted to modulate at least one carrier signal based on the modulation symbols and a sending unit (104) adapted to send the modulated carrier signal.

Abstract: A system and method for controlling modulation. The system includes a plurality of modulators and a transmitting unit. The plurality of modulators decodes data from a data signal and also encodes the data into a clock signal. The transmitting unit transmits the encoded clock signal. According to the system and method disclosed herein, the present invention provides optimized coding efficiency while minimizing overall power consumption.

Abstract: Multi-dimensional space Gray code maps for multi-dimensional phase modulation as applied to LDPC (Low Density Parity Check) coded modulation. A novel approach is provided within LDPC coded modulation communication systems that employ multi-dimensional phase modulation, using m-D (multi-dimensional) Gray code maps, to provide for improved performance when compared to communication systems employing 1-D (single-dimensional) Gray code maps. This approach can generate all possible m-D Gray code maps for a 2m-D M PSK modulation system. For example, all of the 2-D Gray code maps may be generated for a communication system using 4-D 8 PSK modulation system (where m=2, and M=8). A variety decoding processing approaches may be employed to perform LDPC coded modulation decoding of multi-dimensional space Gray code mapped signals. The slightly increased decoding complexity (when compared to decoding 1-D Gray code mapped signals) is the computation of symbol metrics and their decomposition to bit metrics.

Abstract: A transmitter adopting a polar loop system including a phase control loop for controlling the phase of a carrier signal outputted from a transmitting oscillator and an amplitude control loop for controlling the amplitude of a transmitting output signal outputted from a power amplification circuit, and designed to be capable of performing transmission using a GMSK modulation mode and transmission using an 8-PSK modulation mode. In the transmitter, the phase control loop is shared as a phase control loop for use in the GMSK modulation mode and a phase control loop for use in the 8-PSK modulation mode. A component similar to any one of components constituting a loop filter is provided in parallel therewith so that the component can be connected or disconnected in accordance with the modulation mode, for example, by use of a switching element.

Abstract: A digital polar transmitter includes a baseband processor configured to receive an input signal and to convert the input signal into a baseband amplitude component and a baseband phase component. The transmitter also includes a phase modulator in communication with the baseband processor. The phase modulator is configured to modulate an RF carrier signal based on the phase component and to generate a phase-modulated RF carrier signal. A power amplifier is provided in communication with the baseband processor and the phase modulator. The power amplifier is configured to amplify the phase-modulated RF carrier signal based on the baseband amplitude component and to generate an amplified RF signal. The transmitter also includes a digital feedback loop in communication with the power amplifier and the baseband processor. The digital feedback loop is configured to detect the amplified RF signal and to provide a digital amplitude feedback signal and a detected phase feedback signal to the baseband processor.

Abstract: A transmitter and method is provided for digitally upconverting a baseband digital signal to a modulated intermediate frequency (IF) digital signal and sigma-delta modulating the IF digital signal. The baseband digital signal is split into N phases, as can be accomplished using a polyphase interpolation technique (polyphase filter), and modulated. The modulated N phases are not recombined and each phase is further modulated, as can be accomplished using a digital-to-digital sigma-delta modulator that generates digital output signals at the same rate. A high speed digital multiplexer multiplexes the digital output signals into a single bit stream at a higher rate for subsequent power amplification and RF transmission.

Abstract: Certain aspects of a method and system for using a phase locked loop (PLL) as a filter in a wideband polar transmitter may be disclosed. Aspects of the method may include polar modulating a signal by generating a modulated intermediate frequency (IF) signal utilizing a direct digital frequency synthesizer. The modulated IF signal may be upconverted to a radio frequency (RF) signal utilizing a phase locked loop, and the RF signal may be amplitude modulated. The phase locked loop may be enabled to filter the RF signal.

Abstract: A method of beamforming comprising: transmitting a plurality of signals from a transmitter, each signal being transmitted over a plurality of subcarriers, each subcarrier having a weight factor associated therewith; receiving the plurality of signals at a receiver; and for each signal: analyzing the received signal in order to obtain its phase profile, the phase profile comprising the phase for each subcarrier; calculating a plurality of parameters representing the phase profile, the plurality of parameters being less in number than the number of subcarriers; sending the plurality of parameters back to the transmitter; reconstructing a representation of the phase profile at the transmitter using the plurality of parameters; and adjusting the weight factor of each subcarrier using the reconstructed representation of the phase profile, wherein further signals are transmitted by the transmitter using the adjusted weight factors.

Abstract: According to an embodiment of the invention, a method and apparatus for signal modulation are described. According to an embodiment of the invention, a method comprises producing and transferring a modulated signal. The modulation of the signal is over a plurality of amplitude levels, including at least a first amplitude level, a second amplitude level and a third amplitude level, and over a plurality of time slots, including at least a first time slot, a second time slot, and a third time slot. The modulated signal transitions from the first amplitude level to the second amplitude level in the first phase slot, remains at the second amplitude level in the second time slot, and transitions from the second amplitude level to the third amplitude level in a third time slot.

Abstract: Provided is a transmission circuit which is capable of compensating for an offset voltage and a sensitivity characteristic of a PA, and operating with low distortion and high efficiency. A regulator 18 supplies, to a PA 201, a voltage which is controlled in accordance with an amplitude signal to which a first offset value has been added. A regulator 19 supplies, to a PA 202, a voltage which is controlled in accordance with an amplitude signal to which a second offset value has been added. The PA 201 amplifies, in accordance with the voltage supplied from the regulator 18, a phase-modulated signal outputted from a phase modulator 13. The PA 202 amplifies, in accordance with the voltage supplied from the regulator 19, an output signal of the PA 201. A digital block 11 controls the first and second offset values in accordance with temperature information T measured by a temperature measuring section 21.

Abstract: A simplified scrambling scheme that unifies all signals of a satellite broadcasting system, including frame header (404), frame body (402) and pilot symbols (408) with a common reference phase. This results in the simplification and increased flexibility of the receiver front-end design without affecting the overall system performance. In many current communications systems with frame headers and pilot symbols, the phases of frame headers and pilot syrnbols are not designed to be aligned with any constellation points of the modulated data from the frame body. This scrambling scheme takes into account possible impact due to irregular phase changes between frame headers/pilot symbols and modulated data.

Abstract: There is provided a method for hierarchical modulation relating to a first signal, a second signal, and an original constellation having a plurality of symbols in a non-uniform 8 Phase-Shift-Keying (PSK) configuration. Quadrature-Phase-Shift-Keying (QPSK) modulation is used for the first signal and Binary-Phase-Shift-Keying (BPSK) modulation is used for the second signal. The method includes the step of replacing at least some of the plurality of symbols with at least one radial-type QPSK-BPSK constellation.

Abstract: The present invention provides a radio transmitter having a digital modulator that further includes logic for continuous amplitude and continuous phase modulation switching in an RF transmitter intended to support both frequency shift keying (FSK) and phase shift keying (PSK) modulation techniques in a smooth and continuous manner that does not violate spectral mask requirements. The invention supports continuous modulation switching both ways, i.e., from FSK to PSK and from PSK to FSK. In operation, the radio transmitter initially operates in a first communication mode, transmitting communication signals to a remote agent according to a first modulation technique at a first data rate and then transitions to the second modulation type at a second data rate without spectral mask violation.

Abstract: A method and apparatus for compensating for a mismatch in a radio frequency (RF) quadrature transceiver using a direct-conversion scheme is provided. The method includes setting an amplification gain for a baseband quadrature signal to be larger than an amplification gain for a baseband in-phase signal in a reception module; receiving only a baseband in-phase signal in a transmission module; and compensating for a phase mismatch on a basis of a signal output from a quadrature output port. The apparatus includes a phase mismatch compensator which sets an amplification gain for a baseband quadrature signal to be larger than an amplification gain for a baseband in-phase signal in a reception module, inputs only a baseband in-phase signal to a transmission module, and compensates for a phase mismatch on a basis of a signal output from a quadrature output port.

Abstract: A system in which one or more alarm sources (10) can wirelessly communicate with a receiver (30) to activate an alarm and does not contain any identification that indicates the communication's source (10). The system may include “repeaters” (40) whose function is to relay the communication from one station to another over distances longer than can be reached by a single transmitter (10). Apparatuses for transmitting (10), repeating (40), and receiving (30) are also disclosed, as well as a communication system comprised of various elements of these.

Abstract: A polar transmitter includes a digital processor coupled to receive a complex modulated digital signal and a feedback signal produced from the complex modulated digital signal and that is operable to compare the complex modulated digital signal to the feedback signal to determine an error signal indicative of a difference between the complex modulated digital signal and the feedback signal. The digital processor is further operable to produce a correction signal from the error signal and to add the correction signal to the complex modulated digital signal to produce a corrected complex modulated digital signal.

Abstract: An approach is provided for generating Low Density Parity Check (LDPC) codes. An LDPC encoder generates a LDPC code with an outer Bose Chaudhuri Hocquenghem (BCH) code. For ? rate, the relevant parameters are as follows: q=120, nldpc=64,800, kldpc=nBCH=21600, kBCH=21408 (12 bit error correcting BCH). For ¼ rate, the LDPC code has the following relevant parameters: q=135, nldpc=64,800, kldpc=nBCH=16200, kBCH=16008 (12 bit error correcting BCH). For ? rate, the following parameters exist: q=108, nldpc=64800, kldpc=nBCH=25920, kBCH=25728 (12 bit error correcting BCH). The above approach has particular application in digital video broadcast services over satellite.

Abstract: Aspects of a method and system for digital tracking in direct and polar modulation are presented. Aspects of the system may include at least one circuit within a phase locked loop (PLL) circuit that enables adaptive and digital control of an analog fractional N (Frac N) PLL during direct modulation of a signal or polar modulation of the signal.

Abstract: A phase lock loop receives a baseband signal which has an input frequency, and modulating the baseband signal to be a corresponding RF signal which has a predetermined transmission frequency for transmitting. The phase lock loop comprises a programmable divider, a modulator, a phase detector, a charging pump, a loop filter, a voltage-controlled oscillator and a frequency converter. The programmable divider divides the frequency of a local oscillating signal by a programmable divisor to generate a reference signal. The modulator receives the baseband signal, modulates the frequency of the reference signal according to the baseband signal, and generates a corresponding first comparison signal. The frequency converter receives the feedback RF signal and the local oscillating signal and outputs the second comparison signal according to the frequency difference. The divisor of the divider is programmable to avoid the spur frequency being generated because the local oscillating signal is interfered.

Abstract: An input digital signal is periodically and alternately subjected to first modulation and second modulation, being thereby converted into a pair of a baseband I signal and a baseband Q signal. The first modulation and the second modulation are different from each other. The pair of the baseband I signal and the baseband Q signal are outputted. The first modulation may be at least 8-signal-point modulation while the second modulation may be phase shift keying.

Abstract: The present invention discloses an apparatus and a method of modulating a carrier with digital information having a series of datums represented in a plurality of symbols, the method comprising selecting a first number of half-periods of a first phase distinguished carrier signal for representing a corresponding symbol of a first one of the datums, selecting a second number of half-periods of a second phase distinguished carrier signal for representing a corresponding symbol of the datum following the first datum, determining at least one matching carrier signal having a third number of half-periods of a format to conform to a transition of the first phase distinguished carrier signal to the second phase distinguished carrier signal, and sequentially arranging the first number of half-periods of the first phase distinguished carrier signal, the third number of half-periods of the matching carrier signal and the second number of half-periods of the second phase distinguished carrier signal.

Abstract: A transmission apparatus includes a frame configuration determiner that determines a modulation system from among a plurality of modulation systems on a communication situation. A first symbol generator modulates a digital transmission signal according to the modulation system determined by the frame configuration determiner and generates a first symbol, the first symbol comprising a first quadrature baseband signal. A second symbol generator modulates the digital transmission signal according to a predetermined modulation system and generates a second symbol, the second symbol comprising a second quadrature baseband signal.

Abstract: When a transmitting oscillator is built in a communication semiconductor integrated circuit device like a high-frequency IC constituting a wireless communication system, the system prevents degradation of the accuracy of control on the output power of a power amplifier due to noise jumped from an output pin of the transmitting oscillator to an input pin for a detected signal (feedback signal) of an output level of the power amplifier. The transmitting oscillator is built in the high-frequency IC. The detected signal of the output level of the power amplifier, which is detected by a coupler, is attenuated to a level slightly higher than the level of noise jumped from the output pin of the transmitting oscillator to the input pin for a feedback signal of an amplitude control loop, which in turn is inputted to the feedback signal input pin of the high-frequency IC.

Abstract: A baseband shaping device includes a plurality of coefficient memories, each memory having an input address bus, a multiplexor input and a coefficient value output. The device further includes a plurality shift registers, each having an input coupled to a respective one of the coefficient value outputs, a digital to analog clock input and an output. The device further includes a plurality of negative value circuits, each circuit having an input coupled to a respective one of the first shift register outputs and an output, a plurality of multiplexors, each having a first input coupled to a respective one of the first shift register outputs and a second input coupled to a respective one of the output of the plurality of negative value circuits. The device further includes a plurality of second shift registers, and an adder having a plurality of inputs coupled to the plurality of second shift registers.