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: Methods and apparatus for computing the carrier frequency of a transmitter using frequency modulated digital data to compensate for frequency shifting of the transmitter and the receiver local oscillators and for bandwidth adjustment of the receiver's filter. In particular, methods and apparatus are disclosed for binary systems transmitting “1” and “0” data using decoded or undecoded received signals.

Abstract: A method of generating preamble sequence is disclosed. A channel used by a wireless device may be divided into four sub-channels, and the method includes forming a preamble sequence of a first sub-channel, making three replicas of the preamble sequence of the first sub-channel, each replica with a phase rotation of a first angle, a second angle, and a third angle respectively, for forming each preamble sequence of a second sub-channel, a third sub-channel, and a fourth sub-channel, and arranging the preamble sequences of the first, the second, the third, and the fourth sub-channels to form a preamble sequence of the channel.

Abstract: A wall control interface for power management includes a transmitting circuit that generates a switching signal to control a switch and achieve a phase modulation to a power line signal in response to a transmitting-data. A receiving circuit is coupled to detect the phase of the power line signal for generating a data signal and a receiving-data in response to the phase of the power line signal. The receiving circuit further generates a control signal to control power of a load in accordance with the data signal or the receiving-data. The phase modulation is achieved by controlling a turn-on angle of the power line signal. The switch remains in a turn-on state during the normal condition, which achieves good power and low current harmonic. The phase modulation is only performed during the communication of the power management.

Abstract: A technique involves using a fast Fourier transform (FFT) module to transform multiple different types of signals. This may be accomplished using one or more of three techniques: logic within the FFT module can enable different processing depending upon a processing state, the FFT module can be called iteratively to transform a signal that is larger than the FFT implemented in the FFT module, the FFT module can be used for parallel transformation of multiple signals that are smaller than the FFT implemented in the FFT module. Thus, a single FFT module can be used to transform a first type of signal (e.g., WIFI) and a second type of signal (e.g., GPS) if configured according to the technique.

Abstract: An approach for reliably communicating over a satellite in support of a communication service including, for example, as direct broadcast satellite and data service, is disclosed. An input message is encoded, yielding a structured Low Density Parity Check (LDPC) coded message. The coded message is modulated according to a high order modulation scheme that has a signal constellation representing more than two symbols per signaling point—e.g., 8-PSK (Phase Shift Keying) and 16-QAM (Quadrature Amplitude Modulation). The system includes a transmitter configured to propagate the modulated signal over the satellite. The above approach is particularly applicable to bandwidth constrained communication systems requiring high data rates.

Abstract: Provided is a transmitter including a polar modulation circuit which adjusts a timing lag between an amplitude component and a phase component more accurately than a conventional art. The polar modulation circuit includes: a first calculator for performing an exclusive OR logical operation between the amplitude component before and after being inputted to the first processing section; a second calculator for performing an exclusive OR logical operation between the phase component before and after being inputted to the second processing section; and a delay fluctuation detection/compensation section for obtaining a delay time of the amplitude component based on an amount of output accumulation of the first calculator; obtaining a delay time of the phase component based on an amount of output accumulation of the second calculator; detecting an amount of delay fluctuation by using the delay times; and adjusting timings of the amplitude component and the phase component.

Abstract: In a first embodiment of the present invention, a method for communicating main and auxiliary data over a transmission medium is provided, the method comprising: generating a low-frequency output pattern using a high-frequency oscillator, wherein the low-frequency output pattern contains the auxiliary data encoded in a first scheme, wherein the first scheme resembles an output pattern that would be generated by a low-frequency oscillator; sending the low-frequency output pattern through a transmitter to be transmitted over the transmission medium; generating a high-frequency signal using a high-frequency oscillator, wherein the high-frequency signal contains the main data encoded in a second scheme different than the first scheme; and sending the high-frequency signal through the transmitter to be transmitted over the transmission medium.

Abstract: Disclosed herein is a wireless transmission system including a plurality of antenna pairs; a demodulation functional unit; and a transmission characteristic correction unit. The plurality of antenna pairs each including a transmission antenna and a reception antenna. A wireless signal transmitted from a transmission antenna directly arrives as a desired wave at a corresponding reception antenna. Meanwhile, a wireless signal transmitted from a different transmission antenna directly arrives as an unnecessary wave at the reception antenna. The demodulation functional unit corresponding to each antenna pair demodulates a modulation signal received by the reception antenna.

Abstract: Peak power is reduced without causing degradation of EVM. A multi-carrier transmission apparatus comprises: a first amplitude suppression unit suppressing amplitude of an oversampled multi-carrier signal; a first Fourier transform unit transforming an output signal of the first amplitude suppression unit into a frequency domain; a first signal suppression unit suppressing a signal outside a band of the output signal from the first Fourier transform unit under a predetermined condition; and a first inverse Fourier transform unit receiving a multi-carrier signal with respect to a signal within the band, receiving the output signal of the first signal suppression unit with respect to a signal outside the band, and inverse Fourier transforming these received signals.

Abstract: Phase of an output signal is based on comparison of an oscillating signal with an adjustable threshold. Here, adjustment of the threshold results in a corresponding adjustment of the phase of the output signal. For example, the adjustable threshold may comprise an adjustable bias signal for a transistor circuit whereby the oscillating signal is provided as an input to the transistor circuit and the output of the transistor circuit provides the output signal. In some aspects these phase adjustment techniques may be employed to provide one or more tunable multiphase clocks.

Abstract: A method includes receiving from a first station at a second station at least two space-time coded signals in respective formed beams of a multi-beam antenna array associated with the first station; receiving from the first station, in a signaling channel, a value representing a transmit power level; determining power control coefficients for each of the space-time coded signals; and transmitting the power control coefficients to the first station, wherein the control coefficients are for in part adjusting transmit power.

Abstract: A communication apparatus carries out multicarrier communication with another communication apparatus through a transmission channel. The communication apparatus includes a first communication unit which carries out communication using a subcarrier at a first frequency band; a second communication unit which carries out communication using a subcarrier at a second frequency band higher than the first frequency band; and a third communication unit which carries out communication by synchronizing the first communication unit with the second communication unit and concurrently using the first and second frequency bands.

Abstract: A system and method for employing a six-bit rank 1 codebook for four transmit antennas is provided. A method for communications device operation includes estimating a communications channel between the communications device and a controller serving the communications device, thereby producing a channel estimate, quantizing the channel estimate using a codebook, thereby producing a selected codeword, and transmitting an index corresponding to the selected codeword from the codebook to the controller. The codebook includes a plurality of first level codewords, and each first level codeword includes a plurality of subsidiary codewords.

Abstract: A disclosed base station apparatus is capable of communicating with a user equipment terminal in a multi-input multi-output (MIMO) mobile communication system using Pre-coding. The base station apparatus includes a receiving unit receiving a Pre-coding Matrix Indicator (PMI) indicating a specific Pre-coding matrix, a determination unit determining a value of a flag indicator indicating whether the Pre-coding matrix specified in the PMI is to be used for downlink communications, a control signal generation unit generating a downlink control signal including at least the flag indicator, and a transmission unit transmitting a signal including the downlink control signal in downlink.

Abstract: A wireless communication system comprises a wavelet analyzer and a wavelet signal generator. The wavelet analyzer is operable to analyze wireless signals within a frequency and time map of a communications spectrum, whereby the wavelet analyzer is adapted to determine one or more available cells within the frequency and time map. The wavelet signal generator is operable to generate one or more wavelet signals for transmission within the determined one or more available cells of the frequency and time map based on the analyzed wireless signals within the frequency and time map.

Abstract: The present invention discloses a method for generating a signal stream in a multiple-input-multiple-output (MIMO) channel of a wireless communications system. The method comprises encoding at least one transmitting message into a first signal sequence, transforming the first signal sequence into a second and a third signal sequence by a first and a second predetermined rule, respectively, coupling the second signal sequence to a first antenna, coupling the third signal sequence to a second antenna, transmitting a signal stream comprising the first and second signal sequences to a mobile station.

Abstract: A carrier state modulator system is described in which a stream of digital data bits is encoded by modulating the amplitude or phase of a carrier wave. A transmitter modulates the amplitude of a selected number cycles of the carrier in accordance with the state of each digital data bit. A receiver decodes the carrier state modulated signal by determining a phase score for the specified number of cycles of the modulated signal, the phase score based on a number of samples of the amplitude on a positive side of each cycle of the modulated signal that is above a selected amplitude and a second number of samples of an amplitude on a negative side of each cycle of the modulated signal that is below the selected amplitude. The value of the encoded digital data bit of the modulated signal is determined from the phase score.

Abstract: Improvement of transmission efficiency is sought by stopping transmission of unnecessary MLI data. A transmitting circuit 111 in a base station apparatus 110 has an MLI modulation part 248 composed of an MLI generating circuit 238, a symbol modulation circuit 239, and an IFFT circuit 240, a user data modulation part 249 composed of an encoder circuit 234, a symbol modulation circuit 235, a transmission power control circuit 236, and an IFFT circuit 237, and a transmission operation control circuit 113. The transmission operation control circuit 113 controls operation timing of the MLI modulation part 248, the user datamodulationpart 249, and a multiplexer 243 based on a signal to notify that ACK input from a receiving circuit 112 has been received so that slots containing no MLI data are generated.

Abstract: A Digitial Radio Mondiale (DRM) receiver and demodulation method includes a programmable downsampler and a programmable N-point Fast Fourier Transform (FFT) to recover and demodulate the OFDM symbols in a received DRM-encoded RF signal. The received signal is digitally sampled at a rate operably integer downsampled to achieve a number N samples in the useful portion of the OFDM symbol for input to an N-point FFT, where N equal to a power of two. The downsampling rate and size (N-points) of the FFT depend on the DRM encoding and transmission parameters, notably the robustness mode and spectrum occupancy. This reduces the processing/computational requirements and the design complexity of the DRM receiver.

Abstract: A nonlinear filter includes: a determination unit that determines, based on I and Q signals inputted into the determination unit, whether or not to perform pulse insertion; a rotation detector that detects a rotation direction of the I and Q signals on an IQ plane with respect to the origin of the IQ plane; a pulse generator that generates, when the determination unit determines to perform the pulse insertion, a pulse of which at least one of the direction and the magnitude is determined in accordance with at least the detected rotation direction; and an adder that inserts the pulse into the I and Q signals and outputs resultant I and Q signals.

Abstract: A circuit for communicating information in a wireless network includes a filtering circuit in communication with a zero intermediate frequency (ZIF) transceiver circuit. The filtering circuit includes a first mixer in communication with an output of the ZIF transceiver circuit. The filtering circuit includes a first Surface Acoustic Wave (SAW) filter circuit in communication with an output of the first mixer. The filtering circuit includes a second mixer in communication with an output of the first SAW filter circuit. The filtering circuit includes a third mixer, and a second SAW filter circuit in communication with an output of the third mixer. The filtering circuit includes a fourth mixer in communication with an output of the second SAW filter circuit and an input of the ZIF transceiver circuit. The filtering circuit also includes a local oscillator circuit in communication with the first, second, third and fourth mixers.

Abstract: A method and apparatus for estimating a carrier frequency offset (CFO) in a Digital Radio Mondiale receiver is provided. Orthogonal frequency-division multiplexing (OFDM) demodulation is performed on a received DRM signal to produce OFDM symbols. A cell characteristic in corresponding cells in the OFDM symbols is compared and a carrier index of a frequency pilot cell in the cells is identified based upon the compared cell characteristic. The CFO is estimated based on the identified carrier index of the frequency pilot cell. The ratio of values of the cell characteristic in corresponding cells may be calculated and the frequency pilot cell identified by identifying cells for which the cell characteristic is most nearly equal. The CFO may be estimated by comparing the identified carrier index with an expected carrier index of a frequency pilot cell.

Abstract: In one embodiment, a circuit comprises a first inductor-capacitor based voltage-controlled oscillator (LCVCO) generating a first periodic signal with a first frequency and a first phase and a second LCVCO generating a second periodic signal with a second frequency and a second phase, and the second phase is offset relative to the first phase by a 90 degrees offset.

Abstract: A wireless communication device (1) comprises a spatially-multiplexed PSC extracting section (8) for extracting a spatially multiplexed known pilot subcarrier signal (S5) from the received multicarrier-modulated signal, a reference signal generating section (7) for generating a reference signal (S4) of the spatially-multiplexed pilot subcarrier signal, and a phase compensating section (9) for compensating the phase difference of the received signal (S1) according to the pilot subcarrier signal (S5) extracted by the spatially-multiplexed pilot subcarrier extracting section (8) and the reference signal (S4). Therefore, even if a pilot subcarrier signal is spatially multiplexed and transmitted, phase difference detection and phase compensation can be performed by a simple constitution.

Abstract: A signal transmission device includes: at least one of a first communication device that transmits a control signal as a wireless signal and a second communication device that receives the wireless signal transmitted from the first communication device to reproduce the control signal, wherein the wireless signal for the control signal is transmitted separately from a wireless signal for a transmission subject signal which is transmitted between a third communication device and a fourth communication device.

Abstract: A device article and method for an open loop calibrated phase wrapping phase modulator. A tapped delay line may provide a coarse resolution for one or more phases of a signal. A phase multiplexer may receive one or more coarse phases from the tapped delay line and select a coarse phase to send to the digitally controlled delay line. A digitally controlled delay line may provide a fine resolution to the coarse phase from the phase multiplexer.

Abstract: A receive station of the present invention despreads a received signal over both long and short despreading periods to determine individual channel estimates over each symbol period of an extended period for multiple pilot signals. As a result, the present invention provides channel estimates sufficient for both slow and fast fading conditions. The receive station determines an average channel estimate for each of the pilot signals over the extended period by despreading the received signal over the extended period using mutually orthogonal extended spreading sequences. The receive station further determines a combined channel estimate for the pilot signals over each symbol period of the extended period by despreading the received signal over each symbol period using a common spreading sequence. Based on the average and combined channel estimates, the receive station determines individual channel estimates for each pilot signal over each symbol period of the extended period.

Abstract: A transmit circuit reduces undesired amplitude modulation (AM) in transmit signal pulses by substituting predetermined amplitude information for actual pulse amplitude information during portions of the pulse corresponding to nominally constant amplitudes. For example, GMSK and certain other modulation formats use a desired transmit pulse shape that includes a nominally flat middle portion. An exemplary AM reduction circuit detects generated pulse values corresponding to the nominally constant-amplitude portions of the transmit pulse and substitutes predetermined, preferably constant, amplitude values in their place. As such, the circuit may include a comparator used to detect the pulse values corresponding to variable amplitude portions of the pulse, which it passes through, and to detect those amplitude values corresponding to constant-amplitude portions of the pulse, which it replaces with substituted values. Such operation may include amplitude value filtering, and such operations may be modal, e.g.

Abstract: A method for selecting a frequency band, from among a plurality of frequency bands controllable by a radio network controller (RNC), to carry a data communication. The method may include obtaining frequency band usage measurements for a plurality of frequency bands, and using the frequency band usage measurements to select a particular frequency band of the plurality of frequency bands to carry the data communication. Frequency band usage measurements may be based on how many idle slots (and/or data channels) are carried through each of the plurality of frequency bands during a measurement time period. A comparison of the frequency band usage measurements can be used to determine which frequency band sent the greatest number of idle slots (or the fewest number of data channels). The method provides for selecting a frequency band best suited (e.g., has the most available capacity for carrying a data communication) for carrying the data communication.

Abstract: In order is to generate a pilot signal for estimating a transmission characteristic of a transmission channel suitable for OFDM/OQAM multicarrier modulation, a phase reference pilot symbol of which a modulation amplitude is suppressed to zero, and an amplitude reference pilot signal obtained through modulation performed by using an amplitude known to a reception end are transmitted from a transmission end. Further, the transmission characteristic of the transmission channel is estimated and compensated using the phase reference pilot signal and the amplitude reference pilot signal at the reception end. Accordingly, it is possible to simplify a frame generation process performed at the transmission end, and reduce transmission power for the phase reference pilot signal.

Abstract: Disclosed is a binary signal modulator for minimizing deterioration of receiving performance caused by phase error. The binary signal modulator receives binary signals, and converts the binary signals into complex symbols according to a predetermined mapping relation. Here, the mapping relation is generated when a plurality of mapping symbols are arranged on a plurality of trajectories so that the distance between the mapping symbols is greater than or equal to a predetermined distance and the phase between the mapping symbols is greater than or equal to a predetermined angle from among the trajectories starting from a plurality of points on the complex plane, and a distance between the trajectories is greater than or equal to the minimum distance from among the distances between the points.

Abstract: There is an apparatus and technique for generating a sequence of modulated waveforms of finite duration in which the difference in start time of each waveform is shorter than the waveform's overall duration and each waveform in the sequence has independent data modulation imparted upon it. The apparatus consists of a bank of memory cells arranged in an N×M configuration with associated control circuitry, along with an arrangement scheme for the data in the N×M memory cells such that the waveforms will be correctly reproduced when the memory cells are addressed by the control circuitry in the prescribed order.

Abstract: A communications device includes communications data and a training sequence corresponding to a preamble. A modulation and mapping circuit modulates the communications data and training sequence into a plurality of multiple subcarriers that are orthogonal to each other to form an orthogonal frequency division multiplexing (OFDM) communications signal having modulated subcarriers carrying the communications data forming a data payload and modulated subcarriers forming the preamble. The modulation and mapping circuit applies a quadratic modulation to the subcarriers carrying the training sequences to produce a low peak-to-average power (PAPR) preamble of approximately 2.6 decibels (dB) independent of the number of subcarriers.

Abstract: A communications device includes communication data and a training sequence corresponding to a preamble. A modulation and mapping circuit modulates the communications data and training sequence into a plurality of multiple subcarriers that are orthogonal to each other to form an OFDM communications signal having modulated subcarriers carrying the communications data forming a data payload and modulated subcarriers forming the preamble. A pseudo-random signal generator is operative with the modulation and mapping circuit and generates pseudo-random signals based on an encryption algorithm for frequency hopping each subcarrier at an OFDM symbol rate. The modulation and mapping circuit applies a quadratic modulation to the subcarriers carrying the training sequences to produce a low peak-to-average power ratio (PAPR) preamble with a PAPR value of approximately 2.6 decibels (dB).

Abstract: Provided is a modulation device which generates a phase modulation signal and an amplitude modulation signal and can correct an I/Q orthogonal shift and reduce degradation of the ON/OFF ratio. In the device, a phase shifter (174) controls voltage applied to a capacitor in accordance with a control signal outputted from a phase control unit (180) and adjusts the capacitance so as to shift the phase of a carrier generated by an oscillator (173). The phase control unit (180) estimates a phase shift of a phase shifter (174) in accordance with an output RF signal (S140) by using the phase shift estimation method. Furthermore, the phase control unit (180) performs tuning of the phase shifter (174) according to the estimated value of the phase shift of the phase shifter (174) so that a phase difference between carries of an I signal (S125) and a Q signal (S135) is 90 degrees.

Abstract: An approach for reliably communicating over a satellite in support of a communication service including, for example, as direct broadcast satellite and data service, is disclosed. An input message is encoded, yielding a structured Low Density Parity Check (LDPC) coded message. The coded message is modulated according to a high order modulation scheme that has a signal constellation representing more than two symbols per signaling point—e.g., 8-PSK (Phase Shift Keying) and 16-QAM (Quadrature Amplitude Modulation). The system includes a transmitter configured to propagate the modulated signal over the satellite. The above approach is particularly applicable to bandwidth constrained communication systems requiring high data rates.

Abstract: A system and method for encoding data for transmission over a telecommunications network. The system and method involve embedding a control data block (Ik0) within a plurality of real data blocks (IN0). Preferably, real data in the real data blocks (INO) is convoluted with at least some of the control data in the control data block (Ik0) For example, each entry in each real data block (INO) may be phase convoluted with phase angle of the corresponding entry in the control block using an encoding module. Once this is done, the real data in the real data blocks and additionally the control data block in the control block is modulated with every sub carrier.

Abstract: A novel and useful apparatus for and method of local oscillator (LO) generation with non-integer multiplication ratio between the local oscillator and RF frequencies. The LO generation schemes presented are operative to generate I and Q square waves at a designated frequency while avoiding the well known issue of harmonic pulling. A synthesizer provides 4/3 the desired frequency fRF. This frequency is divided by two to obtain in-phase and quadrature square waves at ? fRF. The in-phase signal is divided by two again to obtain in-phase and quadrature square waves at ? fRF. The signals are then logically combined using XOR operations to obtain I and Q branch signals containing spectral spurs. Since the spurs are located in non-disturbing bands, they can be filtered out resulting in the desired output signal.

Abstract: An optical homodyne communication system and method in which a side carrier is transmitted along with data bands in an optical data signal, and upon reception, the side carrier is boosted, shifted to the center of the data bands, and its polarization state is matched to the polarization state of the respective data bands to compensate for polarization mode dispersion during transmission. By shifting a boosted side carrier to the center of the data bands, and by simultaneously compensating for the effects of polarization mode dispersion, the provided system and method simulate the advantages of homodyne reception using a local oscillator. The deleterious effects of chromatic dispersion on the data signals within the data bands are also compensated for by applying a corrective function to the data signals which precisely counteracts the effects of chromatic dispersion.

Abstract: An equalizer for a multi carrier signal for carrying out equalization adapted to each carrier or group of carriers, Fourier transforms the multi carrier signal, and obtains difference terms of the multi carrier signal. Both are input to an adaptive filter, to output equalized signals, wherein decimation is applied to at least some of the difference terms input to the filter. This enables the complexity to be reduced for a given performance level. In particular since only non-zero filter taps need to be stored and updated, coefficient memory and coefficient calculation capacity can be reduced. Another way to reduce complexity involves measuring noise for at least some of the carriers, and dynamically adapting the size of the filter on a per carrier basis according to global optimizion heuristic algorithms which adapt this filter size based on the comparison between this noise and an optimal performance figure achieved in a previous ISI-ICI free measurement phase.

Abstract: Provided is a measuring apparatus which measures a quadrature modulator, including a supplying section supplying the quadrature modulator with a reference I signal having a predetermined frequency and a reference Q signal whose phase is shifted by 90 degrees from the reference I signal, an extracting section extracting, from a modulation signal output from the quadrature modulator by applying quadrature modulation to the reference IQ signals, a main signal component as the reference IQ signals modulated, and an image signal component occurring at a position symmetric to the modulated reference IQ signals with respect to the carrier signal, and a measurement value calculating section calculating at least one of a carrier phase error and amplitude error which occur between I signal and Q signal sides of the quadrature modulator, and a skew between IQ signals of the quadrature modulator, based on the main signal component and image signal component.

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 wireless communication system includes a) a first device having a transmitter part with a Tx-antenna for transmitting an electrical signal having a signal bandwidth BWsig and b) a second device having a receiver part with an Rx-antenna for receiving the transmitted electromagnetic signal. At least one of the Tx- and Rx-antennas is a narrowband antenna having an antenna bandwidth BWant, wherein the Tx- and/or Rx-antenna bandwidths fulfil the relation BWant=k·BWsig. The system is adapted to provide that k is smaller than 1.25, and the antenna bandwidth BWant is defined as the ?3 dB bandwidth of the loaded antenna when it is connected to the communication system, and the signal bandwidth BWsig is defined as the bandwidth within which 99% of the desired signal power is located.

Abstract: Methods and systems for polar modulation using a digital direct frequency synthesizer (DDFS) are disclosed and may comprise generating a phase modulated signal in a DDFS, amplitude modulating the generated phase modulated signal in a non-linear device and transmitting the signal via a wireless medium. A processor may control the generation of the phase and amplitude modulated signals. The non-linear device may comprise a non-linear power amplifier or a mixer. The method may also comprise generating a first phase modulated signal in a first DDFS and generating a second phase modulated signal in a second DDFS, or in a single DDFS with two integrated digital-to-analog converters, and upconverting and combining the first and second phase modulated signals and amplitude modulating the combined upconverted signals in a non-linear device. A processor may be enabled to control the generation of the first and second phase modulated signals.

Abstract: Frequency and phase of an output signal is adjusted to track an input signal. A control signal is adjusted to control a frequency of an oscillating signal from which the output signal is derived. In some aspects the frequency of the oscillating signal is adjusted by reconfiguration of reactive circuits coupled to an oscillator circuit. Phase of the output signal may be adjusted based on comparison of the oscillating signal with an adjustable threshold. For example, the adjustable threshold may comprise an adjustable bias signal for a transistor circuit whereby the oscillating signal is provided as an input to the transistor circuit and the output of the transistor circuit provides the output signal.

Abstract: A system includes a transmitter device that includes a transmitter baseband controller to segment a bit stream into a first segment, a second segment, and a third segment, and generate a first baseband signal that includes the first segment, a second baseband signal that includes the second segment, and a third baseband signal that includes the third segment; and a radio frequency (RF) transmitter to generate a multi-frequency signal based on the first baseband signal, the second baseband signal, and the third baseband signal; and a receiver device that includes an RF receiver to receive the multi-frequency signal, and retrieve the first baseband signal, the second baseband signal, and the third baseband signal from the received multi-frequency signal; and a receiver baseband control to reassemble the bit stream from the received first baseband signal, the received second baseband signal, and the received third baseband signal.

Abstract: A communications receiver may include an adaptive filter unit for removing coherent interference components from a received signal. In the absence of a signal of interest, the filter may adapt dynamically to remove current interference components. When a signal of interest is detected, the filter may be controlled to stop (or at least reduce) its adaptation, to prevent removal of the signal of interest. The received signal may be down-converted to a complex baseband by conditioning circuitry. A detector may detect the signal of interest, and control the filter. Autocorrelation may be used to estimate a characteristic of the signal of interest in the complex baseband. The detector may include hysteresis to react quickly to the start of signal of interest, and more slowly to an end of the signal of interest. The signal of interest may be a frequency shift keyed (FSK) signal. A demodulator may demodulate FSK components based on the autocorrelation result.

Abstract: A telecommunications transmitting device, including: an encoder configured to generate an initial signal formed by at least one reference sequence including an initial integer number of pulses dispatched over a same integer number of time windows; a transmitter configured to transmit the initial signal to a receiver; a demodulation device configured to determine that no acknowledgement from the receiver in response to the initial signal is received; and a processing unit configured to tune a second integer number of pulses constituting a second reference sequence, the second integer number being larger than the initial integer number, wherein the transmitter is configured to transmit a second signal formed by the second reference sequence including the second integer number of pulses dispatched over a same integer number of time windows.

Abstract: A communication system using a length shift keying (LSK) modulation method provides a transmitter having a carrier signal generator for generating carrier signals, and a modulator for modulating lengths of the carrier signals from the carrier signal generator according to combinations of data bits, and a receiver having an integrator for calculating an energy value by integrating the carrier signal that corresponds to a data bit combination, and a data judgment unit for judging the data bit combination by comparing the energy value with a predetermined threshold value. Power is maintained without changing the bandwidth of a communication signal when the communication signal is modulated.