Abstract: A method for transmitting a signal from a transmitter over a channel to a receiver on a Power Line Network, wherein said signal is OFDM-modulated on a set of sub-carriers, is proposed, wherein an OFDM tonemap and an eigenbeamforming encoding matrix are determined based on a channel estimation for each sub-carrier, a tonemap feedback signal and an eigenbeamforming feedback signal are generated, which are descriptive of said OFDM tonemap and said eigenbeamforming encoding matrix, respectively, and transmitted to the transmitter. A corresponding receiver, a transmitter, a power line communication and a power line communication system are described as well.

Abstract: According to one embodiment, a transmitter for transmitting at least one broadcast signal having PLP (Physical Layer Pipe) data includes: a BCH (Bose-Chadhuri-Hocquenghem) encoder configured to BCH encode the PLP data; an LDPC (Low Density Parity Check) encoder configured to LDPC encode the BCH encoded PLP data and output FECFrames (Forward Error Correction Frames); a mapper configured to map data in the FECFrames onto constellations by QAM (Quadrature Amplitude Modulation) schemes; a time-interleaver configured to time-interleave the mapped data; a frame builder configured to build a signal frame including preamble symbols and data symbols; and an OFDM (Orthogonal Frequency Division Multiplexing) modulator configured to modulate data in the signal frame by an OFDM scheme. The PLP data are processed by an LDPC scheme for a long or a short LDPC FECframe. The preamble symbols include signaling information for the time-interleaved PLP data. The data symbols include the time-interleaved PLP data.

Abstract: Systems and methods for orthogonal frequency division multiplexing are provided. In one embodiment, a multi-carrier modem comprises: a receiver configured to de-modulate symbols from at least one of a plurality of spectrally overlapping carrier signals to produce a receiver output; a transmitter configured to modulate symbols onto at least one of a plurality of the spectrally overlapping carrier signals; a processor coupled to the transmitter, wherein the processor outputs data for transmission by the transmitter, wherein the processor applies an inverse Fourier transform to the data transmitted by the transmitter; the processor coupled to the receiver, wherein the processor applies a Fourier transform to the receiver output; and a controller programmed to instruct the transmitter to transmit at least one symbol representing a request for bandwidth allocation on a first carrier; wherein the controller is further programmed to determine when a collision has occurred on the first carrier.

Abstract: Relay nodes relay data from a source node (110) to a destination node (130) in an asynchronous cooperative wireless communication system. Each relay node (120) includes a serial-to-parallel partitioner (212), a row selector (214), a cyclic shifter (216) and an SCBT modulator (218). The serial-to-parallel partitioner partitions symbols corresponding to received information into parallel blocks. The row selector selects one row of a coding matrix for each of the parallel blocks and constructs symbol blocks corresponding to the parallel blocks based on the selected row. The cyclic shifter shifts a cyclic delay of each of the symbol blocks and generates shifted symbol blocks corresponding to the symbol blocks. The SCBT modulator pads a guard interval to each shifted symbol block to remove the effects of asynchronous relay transmission.

Abstract: Methods and systems are provided for timing synchronization for reception of highly-spectrally efficient communications. An example method may include, mapping, in a transmitter, a plurality of transmit bits to a plurality of symbols at a symbol rate that is based on an oscillator signal. The plurality of symbols may be processed via a filter. The processing may result in an inter-symbol correlated (ISC) signal. The oscillator signal may be frequency divided to generate one or more pilot signals having a frequency that is a sub-harmonic of a frequency of the oscillator signal. The pilot signal may be injected into the ISC signal. The injecting may result in an ISC signal with timing carrier. The ISC signal with timing carrier may be transmitted. Gain of the one or more pilot signals may be adjusted based on a spectral mask value associated with the transmitting.

Abstract: Various wireless precoding systems and methods are presented. In some embodiments, a wireless transmitter comprises an antenna precoding block, a transform block, and multiple transmit antennas. The antenna precoding block receives frequency coefficients from multiple data streams and distributes the frequency coefficients across multiple transmit signals in accordance with frequency-dependent matrices. The transform block transforms the precoded frequency coefficients into multiple time domain transmit signals to be transmitted by the multiple antennas. The frequency coefficients from multiple data streams may be partitioned into tone groups, and all the frequency coefficients from a given tone group may be redistributed in accordance with a single matrix for that tone group. In some implementations, the frequency coefficients within a tone group for a given data stream may also be precoded. In some alternative embodiments, tone group precoding may be employed in a single channel system.

Abstract: In a transmission apparatus which multicarrier-modulates and transmits symbols, which are basic units of digital signals, a subcarrier in which a symbol is arranged in a first multicarrier symbol having a first guard interval and a subcarrier in which a symbol is arranged in a second multicarrier symbol having a second guard interval longer than the first guard interval are scattered among a plurality of subcarriers constituting a multicarrier at the same time. Therefore, it is possible to improve the resistance to inter-symbol interference without substantially degrading transmission efficiency.

Abstract: A method of transmitting symbols of a digital transmission constellation from a set thereof, ordered from a smallest to a greatest number of bits per symbol, may include identifying a first constellation from the set that is configured to communicate with a threshold error rate and has a greatest signal-to-noise ratio smaller than a signal-to-noise ratio of a received signal. The method may also include identifying a second constellation from the set that corresponds to a constellation with a number of bits per symbol immediately greater than the first constellation. The method may further include determining first and second probabilities of use of the first and second constellations that would generate an expected number of erroneous bits corresponding to the threshold error rate. The method may further include transmitting a symbol with a constellation selected randomly between the first and second constellations according to the first and second probabilities, respectively.

Abstract: An apparatus comprises a direct digital synthesizer, a mixer having first and second input ports and an output port, and a numerically-controlled oscillator. The direct digital synthesizer has a first output coupled to the first input port of the mixer and a second output coupled to a control input of the numerically-controlled oscillator, and the numerically-controlled oscillator has an output coupled to the second input port of the mixer. The mixer provides a quadrature modulated signal at its output port, and the first and second outputs of the direct digital synthesizer control respective portions of the quadrature modulated signal. For example, the first and second outputs of the direct digital synthesizer may control respective amplitude and phase portions of the quadrature modulated signal.

Abstract: Methods, systems and software are provided for high order signal modulation based on improved signal constellation and bit labeling designs for enhanced performance characteristics, including decreased power consumption. According to the improved signal constellation and bit labeling designs for enhanced performance characteristics, designs for 8-ary, 16-ary, 32-ary and 64-ary signal constellations are provided. According to an 8-ary constellation, improved bit labeling and bit coordinates are provided for a 1+7APSK signal constellation. According to a 16-ary constellation, improved bit labeling and bit coordinates are provided for a 6+10APSK signal constellation. According to three 32-ary constellations, improved bit labeling and bit coordinates are provided for a 16+16APSK signal constellation and two 4+12+16APSK signal constellations.

Abstract: A method of transmitting data in a wireless communication system from a transmitter to a receiver, including the steps of modulating data at the transmitter using a first signal constellation pattern to obtain a first data symbol. The first data symbol is transmitted to the receiver using a first diversity branch. Further, the data is modulated at the transmitter using a second signal constellation pattern to obtain a second data symbol. Then, the second data symbol is transmitted to the receiver over a second diversity path. Finally, the received first and second data symbols are diversity combined at the receiver. A transmitter and a receiver are embodied to carry out the method above.

Abstract: A method and system for optimizing symbol mapping in partial response based communications that are based on use of pulse-shaping that incorporates a predetermined amount of inter-symbol interference (ISI). Optimizing symbol mapping symbol mapping may comprise configuring optimized constellation mapping for use in mapping and/or de-mapping data communicated using the partial response pulse-shaping. In this regard, the optimized constellation mapping may be based on a reference constellation mapping that is utilized for reference modulation scheme, and the configuring comprises applying adjustments to one or more constellation points in the reference constellation mapping. The optimized constellation mapping may be configured to optimize an applicable minimum distance for one or more selected error patterns for a given spectral compression applied during partial response based communications.

Abstract: A log likelihood ratio arithmetic circuit for calculating a log likelihood ratio from information of a coordinate of a reception signal point to be applied to a communication system using a quadrature amplitude modulation method, wherein the circuit limits a scope within which a value of the log likelihood ratio varies corresponding to a position of the reception signal point to a range between adjacent signal points including a hard-decision threshold of a bit, and wherein the value of the log likelihood ratio does not vary outside of the range between the adjacent signal points.

Abstract: A modulator and modulation method are provided, which output an OQAM multi-carrier signal. The method implements a step of transforming, from the frequency domain to the time domain, a set of M symbols of real data so as to output M transformed symbols. The complete transformation includes the following sub-steps: applying a partial Fourier transform to the set of M symbols of real data, outputting a first subset of C transformed symbols, where C is strictly less than M; and obtaining, from the first subset, a second subset of (M-C) transformed symbols that is complementary to the first subset.

Abstract: Wireless communication wherein channel estimation accuracy is improved while keeping the position of each bit in a frame, even when a modulation system having a large modulation multiple value is used for a data symbol. An encoding operation encodes and outputs transmitting data (bit string) and a bit converting operation converts at least one bit of a plurality of bits constituting a data symbol to be used for channel estimation, among the encoded bit strings, into ‘1’ or ‘0’. A modulating operation modulates the bit string inputted from the bit converting operation by using a single modulation mapper and a plurality of data symbols are generated.

Abstract: Disclosed are a phase shifter, a wireless communication apparatus, and a phase control method in which power consumption is reduced. A phase shifter includes a 90° step phase shifter (17) and a 45° phase shifter (18) and adds phase information to two baseband signals to be output to an orthogonal modulator. The 90° step phase shifter (17) contributes to adding any one of phases 0°, 90°, 180°, and 270° to the baseband signals according to a first control signal. The 45° phase shifter (18) contributes to adding one of phases 0° and 45° to the baseband signals according to a second control signal. A phase shifter (8) performs replacement of component signals of one of the baseband signals with component signals of the other of the baseband signals and inversion of polarities of the component signals.

Abstract: A transmitter may be operable to generate a sequence of symbols which may comprise information symbols and one or more pilot symbols. The transmitter may transmit the information symbols at a first power and transmit the one or more pilot symbols at a second power. In instances when a particular performance indicator is below a determined threshold, the first power may be set to a first value and the second power may be set to zero value. In instances when the particular performance indicator is above the determined threshold, the first power may be set to a second value and the second power may be set to a non-zero value. A value of the first power and a value of the second power may be based on an applicable average power limit determined by a communications standard with which the transmitter is to comply.

Abstract: A method for data transmission using spatial-domain modulation, and a transmitter using the same has been proposed. The method comprises the following steps including at least but not limited to receiving a plurality of symbols to be transmitted, mapping the symbols as L-dimensional coordinate, wherein 1<L<N, dividing the antennas into L non-overlapping antenna groups, choosing one activating antenna from the antennas in each of the antenna groups according to the coordinate of the symbols, and transmitting modulated signal by using the activating antenna in each of the antenna groups.

Abstract: An embodiment of the invention provides an electronic device. The electronic device includes a digital-to-analog converter (DAC), a transmitter front-end (TX FE), an amplifier, an analog-to-digital converter (ADC), and a swap circuitry. The TX FE has a first and a second input end coupled to a first and a second output end of the DAC, respectively. The ADC has a first and a second input end coupled to a first and a second output end of the amplifier, respectively. The swap circuitry is configured to couple the first and second output ends of the DAC to a first and a second input end of the amplifier in a normal state, respectively, and couple the first and second output ends of the DAC to the second and first input ends of the amplifier in a swapped state, respectively.

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

Abstract: Various embodiments of a millimeter-wave antenna system configured to enhance the gain in a communication network, in which one or more slotted wave-guides produce radiating slot structures that form accurate high-gain millimeter-wave radiation patterns. The system comprises one or more slotted wave-guides to transport millimeter-waves, a PCB including a substrate lamina and an electrically-conductive lamina with two or more highly accurate slots, and an electrically-conductive metal cover that intersects the electrically-conductive lamina to form an enclosed wave-guide cavity. Various embodiments of methods for producing the millimeter-wave antenna system, including different techniques for creating the accuracy of the slots in the slotted wave-guides.

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

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

Abstract: An apparatus for a transmit end in a wireless communication system is provided. The apparatus includes at least one scrambler configured to scramble a transmission bit stream, wherein the at least one scrambler comprises, a first circulation unit configured to output, during one cycle, at least one bit for scrambling odd-numbered bits of the transmission bit stream and at least one bit for scrambling even-numbered bits of the transmission bit stream, a second circulation unit configured to output, during one cycle, at least one bit for scrambling odd-numbered bits of the transmission bit stream and at least one bit for scrambling even-numbered bits of the transmission bit stream, and operators configured to generate a scrambled bit stream, wherein each of the operators generates a scrambled bit using an input bit, an output bit from the first circulation unit and an output bit from the second circulation unit.

Abstract: A transmitting system, a receiving system, a transmitting method and a receiving method capable of implementing communications with multiple rates are described.

Abstract: Embodiments herein include a method in a user equipment (UE) for transmitting uplink control information in time slots of a subframe over a radio channel to a radio base station. The uplink control information is comprised in a block of bits. The UE maps the block of bits to a sequence of complex valued modulation symbols. The UE block spreads the sequence across Discrete Fourier Transform Spread-Orthogonal Frequency Division Multiplexing (DFTS-OFDM) symbols. This is performed by applying a spreading sequence to the sequence of complex valued modulation symbols, to achieve a block spread sequence of complex valued modulation symbols. The UE further transforms the block-spread sequence, per DFTS-OFDM symbol. This is performed by applying a matrix that depends on a DFTS-OFDM symbol index and/or slot index to the block-spread sequence. The UE also transmits the block spread sequence, as transformed, over the radio channel to the radio base station.

Abstract: A method for estimating transceiver non-idealities is disclosed. In one aspect, the method comprises generating a preamble comprising multiple sets of known training sequences with a synchronization part preceding an estimation part. The training sequences in the estimation part comprises at least two sequences which are (i) complementary Golay sequence pairs and (ii) selected to satisfy a predetermined correlation relationship chosen for estimation of a first non-ideality characteristic. A first estimate of a non-ideality characteristic is determined on the basis of the known training sequences of the synchronization part of the received preamble. The estimation part of the received preamble is compensated by this estimate. Another non-ideality characteristic is determined by the compensated estimation part, exploiting the predetermined correlation relationship.

Abstract: A method and an apparatus for performing hybrid automatic repeat request (HARQ) using constellation rearrangement and a circular buffer in a wireless communication system is provided. An encoded information bit is stored into a circular buffer. A transport block in selected from the circular buffer. A bit set comprising n bits of the transport block is mapped to a data symbol on a constellation for 2n-QAM modulation according to a first mapping order. The bit set is mapped according to a second mapping order when the bits of the transport block are subject to wrap-around at the end of the circular buffer.

Abstract: A transmitting apparatus and method transmits different modulated signals from a plurality of antennas, and employs a configuration that includes a modulation section that obtains a modulated signal by performing signal point mapping of transmit bits using a signal point arrangement that is divided into a plurality of signal point sets on the IQ plane, whereby the minimum distance between signal points within a signal point set is smaller than the minimum signal point distance between signal point sets; and an antenna that transmits a modulated signal obtained by the modulation section. A signal point generating apparatus generates a first and second symbols to be transmitted by first and second antennas, respectively.

Abstract: In RF transceivers a method and system for process, voltage, and temperature (PVT) measurement and calibration are provided. A nominal DC offset current may be generated at a nominal temperature and may be based on a calibration voltage. A nominal transconductance parameter may be determined based on the nominal DC offset current and the calibration voltage. The nominal transconductance may be stored and may be utilized to determine temperature and process conditions during operation. In another embodiment, a plurality of DC offset currents may be generated at different temperatures and these generated DC offset currents may be based on a calibration voltage. The calibration voltage may be constant over the range of temperatures. Transconductance parameters may be determined based on the DC offset currents and the calibration voltage. The transconductance parameters may be stored and may be utilized to determine temperature and process conditions during operation.

Abstract: Disclosed herein are a method and apparatus for generating multiband Radio Frequency (RF) signals in maritime wireless communication. The apparatus includes a baseband conversion unit, a phase compensation unit, a Direct Current (DC) offset compensation unit, and an RF transmission unit. The baseband conversion unit converts RF signals corresponding to a baseband modulation signal having a negative frequency and a baseband modulation signal having a positive frequency into baseband signals, respectively. The phase compensation unit eliminates the images of multiband signals so as to correspond to the baseband signals. The DC offset compensation unit compensates the baseband modulation signals for DC offsets using the multiband signals from which the images have been eliminated The RF transmission unit generates the RF signals using the signals which have been compensated for the DC offsets, and sends the RF signals via an antenna.

Abstract: A transmitter may map, using a selected modulation constellation, each of C? bit sequences to a respective one of C? symbols, where C? is a number greater than one. The transmitter may process the C? symbols to generate C? inter-carrier correlated virtual subcarrier values. The transmitter may decimate the C? virtual subcarrier values down to C physical subcarrier values, C being a number less than C?. The transmitter may transmit the C physical subcarrier values on C orthogonal frequency division multiplexed (OFDM) subcarriers. The modulation constellation may be an N-QAM constellation, where N is an integer. The processing may comprise filtering the C? symbols using an array of C? filter tap coefficients. The filtering may comprise cyclic filtering. The filtering may comprise multiplication by a circulant matrix populated with the C? filter tap coefficients.

Abstract: A transmitter may comprise a symbol mapping circuit that is configurable to operate in at least two configurations, wherein a first of the configurations of the symbol mapping circuit uses a first symbol constellation and a second of the configurations of the symbol mapping circuit uses a second symbol constellation. The transmitter may also comprise a pulse shaping circuit that is configurable to operate in at least two configurations, wherein a first of the configurations of the pulse shaping circuit uses a first set of filter taps and a second of the configurations of the pulse shaping circuit uses a second set of filter taps. The first set of filter taps may correspond to a root raised cosine (RRC) filter and the second set of filter taps corresponds to a partial response filter.

Abstract: A method and apparatus for providing adaptive bearer configuration for MBMS delivery is disclosed. A first aspect of the present disclosure is a method of operating a wireless infrastructure entity (103) wherein a common radio resource (303) is allocated for receiving a response from at least one mobile station (109). A request message, similar to a request for counting, is broadcast to all mobile stations (109) within a coverage area (105). If at least one mobile station (109) responds to the request, PTM transmission mode will be used for MBMS delivery within the given coverage area (105). If more than one mobile station (109) within the coverage area (105) responds to the request, then all the responses will be over the common radio resource (303). The total number of responses to the request message may be limited by providing a probability factor within the request message.

Abstract: A modulation method and device for modulating transfer format combination indicator TFCI information, the method including: dividing equally original TFCI information in a unit of 2 bits in a transmission time interval TTI; extending the resultant respective parts of the TFCI information after the division to correspond to identifiers of one or more designated energy points in a preset constellation; and mapping the respective extended parts of the TFCI information to the corresponding energy points for modulating.

Abstract: Techniques for designing a communications unit including a signal separation module for energy harvesting. In an exemplary aspect, the signal separation module includes first and second quadrature hybrids coupled by band-pass filters (BPF's). Incoming signals within the pass-band of the BPF's are directed through the quadrature hybrids and through the BPF's, and emerge as a desired pass-band signal to be processed by an RX processing module. Incoming signals lying outside the pass-band of the BPF's are reflected from the BPF's back to the first quadrature hybrid, and output as a non-pass-band signal to be processed by an energy harvesting module. In a further exemplary aspect, the signal separation module resides in a detachable module coupleable to a wireless communications device, and a signal transmitted by the wireless communications device is coupled to the signal separation module for energy harvesting.

Abstract: A system and method for estimating a time delay introduced by an envelope tracking amplifier (ETA) of a transmitter. The ETA receives a first baseband signal that is generated by the transmitter and operates on the first baseband signal to produce an output signal. The receiver receives a second baseband signal in response to the transmitter's transmission of the output signal. The receiver generates a model signal that represents an estimate of the first baseband signal. The receiver computes a first time delay between the amplitude envelopes of the second baseband signal and the model signal. The receiver computes a second time delay between phase signals derived respectively from the second baseband signal and the model signal. The receiver estimates the time delay that is introduced by the ETA of the transmitter by subtracting the second time delay from the first time delay.

Abstract: An apparatus and method for scrambling in a wireless communication system are provided. The apparatus includes a selector, a plurality of scramblers, and a plurality of modulators. The selector selects a scrambling scheme to be applied to a transmission bit stream according to a modulation scheme to be applied to the transmission bit stream. The plurality of scramblers scramble the transmission bit stream according to a scrambling scheme corresponding to each of a plurality of modulation schemes. The plurality of modulators modulate the scrambled transmission bit stream according to the plurality of modulation schemes.

Abstract: The method includes generating coded bits by encoding information bits, dividing the coded bits into a first bit-stream and a second bit-stream, generating a first data symbol by performing anti-gray mapping on the first bit-stream, generating a second data symbol by performing gray mapping on the second bit-stream, and transmitting the first data symbol and the second data symbol.

Abstract: A transmitter circuit includes a first synthesizer section, and a second synthesizer section which consumes less current than the first synthesizer section. The transmitter circuit performs switching such that the first synthesizer section is operated and the second synthesizer section is powered off in polar modulation, and the second synthesizer section is operated and the first synthesizer section is powered off in quadrature modulation, thereby reducing consumed power. While the first synthesizer section is operating, calibration for an oscillation frequency is performed, and when the operation is stopped, a calibration value is stored. When an operation of the first synthesizer section is restarted, the stored calibration value is corrected by using temperature change, thereby enhancing calibration accuracy and preventing degradation in quality of a transmission signal.

Abstract: Method and apparatus for configuring a transmitter circuit to support linear or polar mode. In the linear mode, a baseband signal is specified by adjusting the amplitudes of in-phase (I) and quadrature (Q) signals, while in the polar mode, the information signal is specified by adjusting the phase of a local oscillator (LO) signal and the amplitude of either an I or a Q signal. In an exemplary embodiment, two mixers are provided for both linear and polar mode, with a set of switches selecting the appropriate input signals provided to one of the mixers based on whether the device is operating in linear or polar mode. In an exemplary embodiment, each mixer may be implemented using a scalable architecture that efficiently adjusts mixer size based on required transmit power.

Abstract: A processing device processes an analog complex input signal representing a sequence of OFDM symbols in a radio-receiver. The processing device comprises processing paths, each comprising a complex mixer and an analog channel-selection filter. Furthermore, the processing device comprises an oscillator unit that provides local oscillator signals associated with the complex mixer of each processing path. A control unit determines, based on received control data, subcarrier locations, within at least one individual OFDM symbol of the sequence, of one or more resource blocks allocated to the radio receiver. The control unit, for each of the at least one individual OFDM symbol, controls the local oscillator signals based on the determined subcarrier locations and passbands of the channel-selection filters such that each resource block allocated to the radio receiver is frequency translated by a complex mixer of the processing paths to appear within the passband of the following channel-selection filter.

Abstract: A power series digital predistorter and a distortion compensation control method for the power series digital predistorter are capable of adjusting the coefficients of a frequency characteristic compensator at high speed. A controller in the power series digital predistorter collectively sets adjustment amounts for the phases in bands in an N-th order frequency characteristic compensator; collectively sets adjustment amounts for the amplitudes in the bands in the N-th order frequency characteristic compensator; determines whether an index indicating the degree of cancellation of a distortion component generated in a power amplifier satisfies a preset condition; and, if the index does not satisfy the condition, performs control such that the adjustment amounts for the phases and the adjustment amounts for the amplitudes are set again.

Abstract: A balanced transmitter up-converts I and Q baseband signals 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 I and Q baseband signals 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 necessary information to reconstruct the I and Q baseband signals. The differential sampling is performed according to control signals that are phase shifted with respect to each other. The control signals may have pulse widths (or apertures) that operate to improve energy transfer to a desired harmonic in the harmonically rich signal.

Abstract: A communications device may include In-phase (I) power amplifiers configured to generate I amplified signals, Quadrature (Q) power amplifiers configured to generate Q amplified signals, an I controller coupled to the I power amplifiers and configured to selectively enable some of the I power amplifiers, and a Q controller coupled to the Q power amplifiers and configured to selectively enable some of the Q power amplifiers. The communications device may also include a power combiner configured to combine the I amplified signals and the Q amplified signals in a combined amplified signal, and an antenna coupled to the power combiner.

Abstract: Systems and methods for encoding and decoding check-irregular non-systematic IRA codes of messages in any communication or electronic system where capacity achieving coding is desired. According to these systems and methods, IRA coding strategies, including ones that employ capacity-approaching non-systematic IRA codes that are irregular and that exhibit a low error floor, are employed. These non-systematic IRA codes are particularly advantageous in scenarios in which up to half of coded bits could be lost due to channel impairments and/or where complementary coded bits are desired to transmit over two or more communications sub-channels. An encoder includes information bit repeaters and encoders, one or more interleavers, check node combiners, a check node by-pass and an accumulator. A decoder includes a demapper, one or more check node processors, an accumulator decoder, a bit decoder, and one or more interleavers/deinterleavers.

Abstract: A circuit for providing AM/PM modulation is described. The circuit includes a signal generator, which provides two phase modulated (PM) signals used to form two drive signals which are later combined in a constructive/destructive fashion. The combination of the two phase modulated signals form a signal for driving a load. When the load is driven, the resulting signal is AM/PM modulated.

Abstract: Systems and methods for controlling transmission of signals are described. A camera-side modem is configured to receive two signals from a video camera and to extract a received passband signal from a transmission line. A detector in the camera-side modem generates an enable signal when the received passband signal is identified. The enable signal is used to control transmission of at least one of the baseband video signal and the passband video signal. The passband signal may be identified by an estimate of mean square error in a quadrature amplitude demodulator, a measurement of reliability provided by a constellation detector, a measurement of reliability based on a sequence of frame synchronizations and/or an estimate of mean square error in an equalizer. The detector may monitor a gain factor in an automatic gain control module of the camera-side modem and/or a magnitude of the received passband signal.

Abstract: A waveform-adaptive ultra-wideband (UWB) transmitter and noise-tracking UWB receiver for use in communications, object detection and radar applications. In one embodiment, the output of an oscillator is gated by a low-level impulse generator either directly or through an optional filter. In a special case of that embodiment wherein the oscillator is zero frequency and outputs a DC bias, a low-level impulse generator impulse-excites a bandpass filter to produce an UWB signal having an adjustable center frequency and desired bandwidth based on a characteristic of the filter. In another embodiment, the low-level impulse signal is approximated by a time-gated continuous-wave oscillator to produce an extremely wide bandwidth pulse with deterministic center frequency and bandwidth characteristics. The low-level impulse signal can be generated digitally. The UWB signal may be modulated to carry data, or may be used in object detection or ranging applications.

Abstract: An orthogonal complex spreading method for a multichannel and an apparatus thereof are disclosed. The method includes the steps of complex-summing ?n1WM,n1Xn1 which is obtained by multiplying an orthogonal Hadamard sequence WM,n1 by a first data Xn1 of a n-th block and ?n2WM,n2Xn2 which is obtained by multiplying an orthogonal Hadamard sequence W1,n2 by a second data Xn2 of a n-th block; complex-multiplying ?n1WM,n1Xn1+j?n2WM,n2Xn2 which is summed in the complex type and WM,n3+jPWM,n4 of the complex type using a complex multiplier and outputting as an in-phase information and quadrature phase information; and summing only in-phase information outputted from a plurality of blocks and only quadrature phase information outputted therefrom and spreading the same using a spreading code.