Abstract: The present invention relates to a method of transmitting and a method of receiving signals and corresponding apparatus. One aspect of the present invention relates to an efficient L1 signaling method for an efficient transmitter and an efficient receiver using the efficient L1 signaling method for an efficient cable broadcasting.

Abstract: A pulse amplitude modulation (PAM) signal generator that injects a copy of a pulse into the PAM baseband signal prior to frequency upconversion and power amplification. The pulse comprises a function of, or an extra copy of, a pulse in the PAM baseband signal. The pulse injector analyzes the PAM baseband signal for times when a predetermined threshold is exceeded and forms a pulse that is constructed and arranged to reduce the amplitude of the PAM baseband signal to a desired peak amplitude when the pulse is added to the PAM baseband signal. In other embodiments the peak-to-RMS amplitude ratio reducing methods and apparatus used to process PAM signal are adapted for reducing peak-to-RMS amplitude ratios of amplitude modulation signals in polar modulation transmitters. Peak-to-RMS amplitude ratio reduction is performed in the quadrature domain, the polar domain, or both the quadrature and polar domains.

Abstract: A feedback loop is used to determine phase distortion created in a signal by directly extracting the phase distortion information from a feedback signal using original frequency modulation information.

Abstract: Certain aspects of a method and system for a wideband polar transmitter may be disclosed. Aspects of the method may include polar modulating a plurality of signals by generating a plurality of modulated intermediate frequency (IF) signals corresponding to each of a plurality of wireless communication protocols within a transmitter that handles the plurality of wireless communication protocols. The generated plurality of modulated IF signals may be upconverted to a plurality of radio frequency (RF) signals. The plurality of RF signals may be combined and the combined plurality of RF signals may be amplitude modulated.

Abstract: A multiband OFDM_UWB transmitting and receiving apparatus is provided in Low-IF configuration to solve problems attributed to a direct-conversion transmitting and receiving apparatus. A Low-IF receiver performs sorting by rotating a sub-carrier after FFT to eliminate the need for frequency conversion using a second local signal and uses the same AD conversion clock as that for a direct conversion receiver. An FFT-free preamble can be detected by using a sequence resulting from previously multiplying an original preamble pattern and an IF frequency together.

Abstract: An ASK modulator for reducing the difference in the On/Off ratio due to the difference in the envelope frequency components without deteriorating an adjacent wave leakage power is disclosed. The ASK modulator includes a Manchester encoder that generates Manchester-encoded signals by applying Manchester encoding to an input signal sequence, a waveform shaping unit that generates band-limited encoded signals from the Manchester-encoded signals, and detects and limits minimum values of waveforms of the band-limited encoded signals to generates shaped signals, and a modulating unit that modulates carrier waves based on the shaped signals.

Abstract: The present invention relates to receiving control information in an orthogonal frequency division multiplexing (OFDM) system of a mobile communication system. The present invention includes receiving information related to a number of OFDM symbols in a subframe for receiving first control information, receiving information related to a number of OFDM symbols in the subframe for receiving second control information, decoding the first control information according to the received information related to the number of OFDM symbols in the subframe for receiving the first control information, and decoding the second control information according to the received information related to the number of OFDM symbols in the subframe for receiving the second control information, wherein the number of OFDM symbols for receiving the first control information is less than or equal to the number of OFDM symbols for receiving the second control information.

Abstract: Compact pulse shape partial response (CPS PR) signaling is developed for trellis based signals like QM-MSK, and for PAM/QAM type signals to improve the performance to bandwidth tradeoff. Compact pulse shaped signals are partial response signals that employ a very short pulse shaping filter and use Viterbi decoding to optimally detect the CPS signal in presence of its inherent inter-symbol interference. The CPS filters considered herein have much shorter impulse response than the well-known raised cosine (RC) filter. There is no need to equalize the received signal to eliminate ISI or to allow a fixed amount of ISI between received signal samples as sampled at the symbol rate as is common in partial response maximum likelihood (PRML) systems. Numerical results indicate that CPS QM-MSK and CPS QAM provides between several dB of gain, depending on constellation size, over PR-CPM and RC QAM, when compared at a given value of bandwidth, i.e., B99Tb.

Abstract: The disclosure relates to a radio broadcasting method for a first multicarrier digital signal occupying a first frequency band adjacent to at least one second frequency band, each assigned to a second signal. Pre-filtering is applied to the said first signal before its emission so as to attenuate the power of the said first signal in at least a first portion of the said first frequency band, adjacent to the said second frequency band(s).

Abstract: A signal scaling device (D), for a transmission path of a wireless communication equipment, comprises a processing means (PM) adapted to receive a phase and/or amplitude modulated signal (I/Q) to transmit, and arranged to multiply said phase and/or amplitude modulated signal with a chosen complex gain in order to output said phase and/or amplitude modulated signal with a chosen scaled amplitude and a chosen phase offset.

Abstract: Methods and apparatus for reconstructing discrete-time amplitude modulation signals in polar modulation transmitters. An exemplary polar modulation transmitter includes a symbol generator, a rectangular-to-polar converter, a peak phase detector, and an amplitude modulation reconstruction circuit. The symbol generator generates rectangular-coordinate modulation symbols from which the rectangular-to-polar converter generates an amplitude modulation signal containing discrete-time amplitude samples and an angle modulation signal containing discrete-time angle samples. The peak phase detector circuit detects phase reversals or near phase reversals represented in samples of the angle modulation signal. The amplitude modulation reconstruction circuit responds by reconstructing samples in the amplitude modulation signal that correspond to detected phase reversals or a near phase reversals represented in samples of the angle modulation signal.

Abstract: A method, apparatus, and computer program is presented for use in a radio transmitter using a polar transmitter structure in which a transmission signal is separated into an amplitude component and a phase component. The transmission signal includes transmission symbols distributed to a number of transmission resource blocks allocated to the radio transmitter for transmission. The amplitude component of the transmission signal is low-pass filtered in a low-pass filter configured by filtering parameters selected according to the number of transmission resource blocks allocated to the radio transmitter. Then, the low-pass filtered amplitude component is used in power supply of a power amplifier configured to power-amplify a phase component of the transmission signal.

Abstract: Amplitude modulation is provided for a polar transmitter that incorporates a translational loop. The input to the polar transmitter and translational loop may be an amplitude modulated signal. The amplitude modulation of the transmitter may be controlled via a closed loop to help ensure that the output of the amplifier accurately corresponds to the modulated input signal. The transmitter may incorporate partially integrated or separate translational and amplitude modulation loops.

Abstract: Disclosed is a bits-to-symbol mapping method of 4+12+16 amplitude phase shift keying (APSK) having excellent performance against the non-linearity of a high power amplifier. According to the present invention A bits-to-symbol mapping method of 4+12+16 APSK modulation, comprising: representing 32 symbols of the 4+12+16 APSK modulation by a polar coordinate and arranging the 32 symbols by a size of ? while giving priority to a symbol having a small signal size when the size of ? of two or more symbols are same; grouping the arranged 32 symbols into 4 groups according to quadrant regions where the symbols are located; and allocating bits so that the same bits are allocated to the symbols belonging to the same region for each region with respect to each of the first to fifth bits of the symbols grouped into four regions.

Abstract: Provided is a modulation-index adjustable amplitude shift keying (ASK) transmitter including: a bias current supply unit supplying one or more bias currents in response to a digital signal that is to be transmitted and one or more bias current control signals; and a modulation signal generator generating a modulation signal corresponding to the digital signal by modulating a carrier signal in response to the one or more bias currents.

Abstract: According to one exemplary embodiment, a method for producing an up-converted and amplified transmission signal comprises performing a logarithmic transformation of an input transmission signal to form a logarithmically transformed transmission signal, adding the logarithmically transformed transmission signal to a logarithmic local oscillator signal to form a sum signal, and performing an antilogarithmic transformation of the sum signal to produce the up-converted and amplified transmission signal. In one embodiment, a log-antilog circuit for producing an up-converted and an amplified transmission signal comprises a transmission log block configured to receive an input transmission signal and to provide a logarithmically transformed transmission signal as a transmission log block output, and an antilog block coupled to the transmission log block. The antilog block is configured to receive a sum signal of the transmission log block output and a logarithmic local oscillator signal.

Abstract: A method of transmitting data that includes controlling generation of bit sequences to adjust an occupation rate occupied with predetermined bits included in a first data block, which is obtained by encoding first data in a first encoding process, to be equal or closer to an occupation rate occupied with predetermined bits included in a second data block, which is obtained by encoding second data in a second encoding process, in regard to first bit positions of the bit sequences generated using bits included in the first and second data blocks; and performing multi-level modulation for transmission based on the generated bit sequences.

Abstract: Techniques for producing an output signal using an outphasing transmitter are disclosed. In some examples, constant modulation (CM) signals may be produced from a digital input signal. The CM signals may be converted to an analog state and filtered. The signals may then be modulated to produce modulated signals, which may be amplified. The amplified signals may be combined to produce combined signals, which may further be combined to produce an output signal.

Abstract: According to one embodiment, a first encoder encodes main information, a second encoder encodes sub-information, a first modulator modulates a carrier based on an output of the first encoder, a duplicating module duplicates an output of the second encoder to generate encoded sub-information units, and a second modulator amplitude-modulates an output of the first modulator based on the encoded sub-information units. The second modulator amplitude-modulates with ?/(?×(2N)1/2) being 0.4 or less, wherein a noise power of a transmission path or a storage medium is ?2, a number of the encoded sub-information units is N, signal levels after amplitude modulation, which correspond to bit 1 and bit 0 of the encoded sub-information units, are A and B, and a level difference A?B is ?.

Abstract: A transmitter includes an oscillator that generates a clock signal and a mapping unit that maps received data-bits to symbols and designates each of the symbols as three or more signal coding levels, where each of the signal coding levels are represented by a plurality of digital codes. The three or more signal coding levels representing each symbol are DC balanced and include a plurality of peak amplitudes. The transmitter further includes a digital to analog convertor that converts the plurality of digital codes to a corresponding plurality of analog amplitude levels at a rate determined by the clock signal, whereby the analog amplitude levels generate a signal coding level. A filter then smoothes the plurality of analog amplitude levels and generates a modulated carrier wave that is coded by the symbols.

Abstract: A polar modulator including a signal converter configured to provide a phase signal and an amplitude signal based on at least one received signal is disclosed. A digital-to-analog converter is coupled to the signal converter, the digital-to-analog converter configured to receive an augmented signal, wherein a polarity of the augmented signal is selected to minimize an absolute phase change for sequential signals. A signal mixer is coupled to the digital-to-analog converter to receive an analog signal generated from the augmented signal.

Abstract: A transmission circuit is capable of precisely compensating for an offset characteristic of an amplitude modulation section, and operating with low distortion and high efficiency over a wide output electric power range. A signal generation section outputs an amplitude signal and an angle modulation signal. An amplitude amplifying section inputs, to the amplitude modulation section, a signal corresponding to a magnitude of the amplitude signal having been inputted. The amplitude modulation section amplitude-modulates the angle modulation signal with the signal inputted from the amplitude amplifying section, and outputs a resultant signal as a modulation signal. The power measuring section measures an output power of the amplitude modulation section. An offset compensation section reads an offset compensation value from a memory in accordance with the output power of the amplitude modulation section, and adds the read offset compensation value to the amplitude signal.

Abstract: A signal transmission apparatus of the invention comprises: a correlator 12 for shaping a spectrum of a signal; and a precoder 12 disposed on a previous stage of the correlator and including an adder which subtracts an output signal of a feedback filter from an input signal, a modulo arithmetic unit which inputs an output signal of the adder and executes modulo arithmetic operation, and the feedback filter which inputs an output signal of the modulo arithmetic unit and is provided with a transfer function obtained by subtracting 1 from a transfer function of the correlator. The correlator may be IIR filter means having a desired notch characteristic. By disposing a correlator which can freely shape a transmission signal spectrum containing a deep notch and suppress only a specified band on a receiving side, the suppression of an external noise can also be realized.

Abstract: A signal processing system is disclosed. The system includes: a first synthesizer and a second synthesizer, for respectively generating a first frequency and a second frequency; a first RF circuit; a first analog front end (AFE); a second RF circuit; and a second AFE, wherein the first RF circuit and the first AFE can support a signal transmission of a first bandwidth, the second RF circuit and the second AFE can support a signal transmission of a second bandwidth, a central frequency of the first bandwidth is substantially equal to the first frequency, and a central frequency of the second bandwidth is substantially equal to the second frequency.

Abstract: Apparatus is presented for broadcasting an RF signal. This includes a signal divider that receives a composite RF signal and provides therefrom first and second signals each having digital and analog components. A phase extractor receives the first signal and provides therefrom a phase modulated RF signal for application to an amplifier. A gain controller varies the gain of the amplifier in accordance with amplitude variations of the second signal.

Abstract: A transmitter using quadrature modulation includes a rectangular to polar converter for converting data symbols into a polar form, where each polar symbol has a magnitude signal and an angle signal. Digital phase modulation circuitry includes an all digital PLL circuit for generating a phase modulated RF carrier signal responsive to the angle signal frequency control word (FCW) and a carrier frequency FCW. A digitally controlled amplifier for amplifying the phase modulated signal is controlled by a digital amplitude control circuitry for controlling the gain of the digitally controlled amplifier responsive to the magnitude signal.

Abstract: A system and device communicates data. A modulation and mapping circuit modulates and maps data symbols into a plurality of multiple subcarriers that are orthogonal to each other based on a fixed or variable symbol rate. A frequency domain spreader circuit is operatively connected to the modulation and mapping circuit and spreads the multiple subcarriers over the frequency domain.

Abstract: A phase detector includes a plurality of phase detectors located in a phase correction loop, each phase detector configured to receive as input a radio frequency (RF) input signal and an RF reference signal, each of the plurality of phase detectors also configured to provide a signal representing a different phase offset based on the phase difference between the RE input signal and the RF reference signal; and a switch configured to receive an output of each of the plurality of phase detectors and configured to select the output representing the phase offset, that is closest to a phase of an output of an amplifier.

Abstract: A transmitter, a receiver, and a transceiver for use in a wireless communication system are disclosed. In one embodiment, the radio frequency (RF) transmitter comprises a first parallel-to-serial converter to convert first parallel data corresponding to a I quadrature baseband signal component into a first set of serial data bits, a second parallel-to-serial converter to convert second parallel data corresponding to a Q quadrature baseband signal component into a second set of serial data bits, and one or more stages having a first XOR gate coupled to a gate terminal of a first transistor and a second XOR gate coupled to a gate terminal of second transistor. The first XOR gate has a pair of inputs coupled to the first set of serial data bits and a first clock (e.g.

Abstract: A method of reducing the peak-to-mean ratio of a multi-carrier signal includes the steps of: generating a residual signal from the multicarrier signal, the residual signal representing the difference between the multicarrier signal and a hard-clipped multicarrier signal. The method also includes the steps of applying a least squares function to the residual signal for each carrier of the multi-carrier signal, thereby generating a minimized residual signal for each carrier and combining the minimized residual signals and the multicarrier signal.

Abstract: A system and method are provided for calibrating Amplitude Modulation to Phase Modulation (AM/PM) pre-distortion in a transmitter operating according to a polar modulation scheme. In general, phase modulation is disabled during transmission of an actual polar modulation signal. As a result, the transmitter provides a radio frequency (RF) output signal having an amplitude modulation component and ideally a constant phase. However, the AM/PM distortion of the transmitter creates a phase modulation component in the RF output signal. The phase component of the RF output signal, which is the AM/PM distortion of the transmitter, is measured by test equipment. The AM/PM pre-distortion applied by the transmitter is then calibrated based on the measured AM/PM distortion such that the AM/PM distortion of the transmitter is substantially reduced.

Abstract: A method of broadcasting an AM compatible digital audio broadcasting signal includes: producing an analog modulated carrier signal centrally positioned in a radio channel, wherein the analog modulated carrier signal is modulated by an analog signal, producing a plurality of digitally modulated subcarrier signals in the radio channel, wherein the digitally modulated subcarrier signals are modulated using complementary pattern-mapped trellis code modulation (CPTCM) including a code mapped to overlapping partitions including an upper main partition, a lower main partition, an upper backup partition and a lower backup partition, and a non-overlapping tertiary partition, and transmitting the analog modulated carrier signal and the plurality of digitally modulated subcarrier signals. Transmitters that broadcast the signal and receivers that receive the signal, and the reception method are also included.

Abstract: A transmission arrangement for modulating useful signals onto a carrier frequency signal has a frequency generator for generating the carrier frequency signal, a first modulation path for modulating a first useful signal onto the carrier frequency signal, and a second modulation path for modulating a second useful signal onto the carrier frequency signal. The first modulation path has a digital modulator for providing an amplitude signal and a Cartesian signal pair from the first useful signal and a Cartesian modulator for modulating the Cartesian signal pair onto the carrier frequency signal in order to provide an intermediate signal. The first modulation path is configured in such a manner that the amplitude signal is modulated onto the intermediate signal in order to provide an output signal.

Abstract: A spread spectrum cellular network (FIG. 1) mobile unit transmitter (30) that enables communication via protocols having different bandwidth (372) and baseband signal generation (260), the transmitter including a phase locked loop and an amplitude control loop.

Abstract: A frequency synthesizer includes a distributed phase detector circuit, a multiple charge pump, a loop filter, a voltage-controlled oscillator and a dividing circuit. The distributed phase detector circuit delays an up signal and a down signal to generate a delayed up signal and a delayed down signal. The multiple charge pump generates a distributed current signal including a plurality of current pulse signals. Each of the current pulse signal is based on each bit of the delayed up signal and the delayed down signal. The loop filter filters the distributed current signal to generate a control voltage. The voltage-controlled oscillator generates an oscillation frequency signal based on the control voltage. The dividing circuit divides the oscillation frequency signal to generate a plurality of division frequency signals in response to a plurality of control signals, where the frequency signals are fedback to the distributed phase detector circuit.

Abstract: A system and method communicates and generates a Coded Orthogonal Frequency Division Multiplexed (COFDM) communications signal as a plurality of subcarriers. Selected subcarriers are turned ON and OFF while also frequency hopping and spreading the selected ON subcarriers over the frequency domain based on a fixed or variable sample rate to reduce average power for enhanced Low Probability of Interception/Low Probability of Detection (LPI/LPD) and also allow for more transmit power within a spectral mask.

Abstract: A transmission apparatus includes: a multiplier configured to multiply a signal provided on a complex plane by a multiplication coefficient corresponding to a number of transmission sub-carriers; and an inverse fast Fourier transformer configured to perform an inverse fast Fourier transform on the multiplied signal.

Abstract: A method of encoding a stream of data elements is provided which involves splitting the stream of data elements into a first stream and a second stream; encoding the first stream to produce a first encoded stream; performing a constellation mapping using a combination of the first encoded stream and a third stream which is based on the second stream. This may involve defining a signal constellation; defining a plurality of co-sets within the constellation such that a minimum distance between constellation points within each co-set is larger than a minimum distance between any constellation points within the signal constellation; performing said constellation mapping by using the first encoded stream to identify a sequence of co-sets of said plurality of co-sets, and by using the third stream to identify a sequence of constellation points within respective co-sets of the sequence of co-sets identified by said first encoded stream.

Abstract: Sampled IQ values at the origin are revalued by applying a minimum distance, or radius, away from the (0,0) coordinate in the IQ domain, and applying a rotation about the origin for consecutive (0,0) samples, thereby improving communication performance. A direction of rotation is able to be predetermined or dynamically determined according to a correction look-up table or an IQ trajectory.

Abstract: Apparatus and methods for improving the performance of a modulator, typically in an I/Q modulation system, are described. Input I and Q current modulation signals may be processed to generate a sign signal and a magnitude signal, with the magnitude signal selectively applied to the inputs of a mixer based on the sign signal so as to generate respective I and Q modulation signal components. These may then be combined to generate a composite modulation signal.

Abstract: A transmission signal generating unit has a window function calculator that generates a window function that makes all frequencies without a center frequency of an input signal and its adjacent frequencies zero and makes the signal to noise ratio of the center frequency maximum; and a transmission signal generator that generates a transmission signal whose amplitude is modulated in a shape of an envelope curve based on the window function generated by the window function calculator.

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: A hybrid transmitter includes first and second up-conversion modules, a combining module, and a power amplifier circuit. The first up-conversion module is operably coupled to generate a first up-conversion signal based on a normalized in-phase (I) symbol, an in-phase local oscillation, and phase or frequency information. The second up-conversion module is operably coupled to generate a second up-conversion signal based on a normalized quadrature (Q) symbol, a quadrature local oscillation, and the phase or frequency information. The combining module is operably coupled to combine the first and second up-conversion signals to produce a radio frequency (RF) signal. The power amplifier circuit is operably coupled to adjust amplitude of the RF signal based on amplitude information to produce an amplitude and phase modulated RF signal.

Abstract: A wireless multicarrier transmission method in which a multicarrier transmission uses n modulated frequency subcarriers (n is an integer number), and a fading condition of each subcarrier is detected to generate fading channel profile information.

Abstract: A method of transmitting data including controlling generation of bit sequences to adjust an occupation rate occupied with predetermined bits included in a first data block, which is obtained by encoding first data, to be closer to an occupation rate occupied with predetermined bits included in a second data block, which is obtained by encoding second data. With regard to first bit positions of the predetermined bits, the first bit positions being distinguished from second bit positions based on an error tolerance resulting from a correspondence to a signal point on a phase plane. Wherein a sum of a number of the predetermined bits included in the first data block and the predetermined bits included in the second data block is less than a total number of the first bit positions. Also including performing multi-level modulation for transmission based on the generated bit sequences.

Abstract: In a method of allocating digital data (55a, 55b) coming from transponders, a reader (1) receives a first signal (13) that comprises a first signal component (7) coming from a first transponder (2) and a second signal component (8) coming from a second transponder (3). The digital data (55a) coming from the first transponder (2) are encoded in the first signal component (7) and digital data (55b) coming from the second transponder (3) are encoded in the second signal component (8). Second and third signals (10, 11) are generated by subjecting the first signal (13) to an in-phase and to an in-quadrature demodulation. The digital data (55a, 55b) of the first and second transponders (2, 3) are encoded in the second and third signals (10, 11). Clusters (51-54) of the digital data (55 a, 55b) associated with a constellation diagram, which is related to the second and third signals (10, 11), are allocated to the first and second transponder (2, 3).

Abstract: The channel estimates for the subcarriers are used to determine the signal strength distribution in the form of a cumulative histogram. The latter is used to determine, as a signal strength threshold value E, that maximum signal strength whose magnitude is less than or equal to the signal strengths of a predetermined number L of subcarriers which are to be limited, i.e. saturated, in the signal processing path. The signal strength threshold value E and a constant K are used to form a multiplication factor M with which the data signals are weighted or by which the data signals are multiplied, the L subcarriers being limited to a fixed value after multiplication.

Abstract: When transmitting an RF signal for power supply or a pulse signal for data transmission, amplification is made in such a manner that the peak power of the RF signal becomes greater than the peak power of the pulse signal. Thus transmitting the RF signal with the greater peak power enables charging of a capacitor 23 of noncontact wireless communication equipment 2 even if the distance to the noncontact wireless communication equipment 2 is long.

Abstract: A modulator modulates the packet data signal. A correction unit 18 adjusts the amplitude component of the modulated data signal. An amplifier amplifies the adjusted data signal and outputs the data signal. A control unit controls the operation of the amplifier. The control unit turns on the operation of the amplifier at the header timing of a packet. The amplifier generates a transient response in the header part of the packet when the amplifier is turned on. In accordance with the inverse characteristic of the transient response generated in the amplifier, the correction unit adjusts the amplitude component of the modulated data signal.

Abstract: A balanced transmitter up-converts a baseband signal directly from baseband-to-RF. The up-conversion process is sufficiently linear that no IF processing is required, even in communications applications that have stringent requirements on spectral growth. In operation, the balanced modulator sub-harmonically samples the baseband signal in a balanced and differential manner, resulting in harmonically rich signal. The harmonically rich signal contains multiple harmonic images that repeat at multiples of the sampling frequency, where each harmonic contains the necessary information to reconstruct the baseband signal. The differential sampling is performed according to a first and second control signals that are phase shifted with respect to each other. In embodiments of the invention, the control signals have pulse widths (or apertures) that operate to improve energy transfer to a desired harmonic in the harmonically rich signal.