Abstract: Disclosed is a system and method for power line control of electrical fans. The system generates a sinusoidal wave using a crystal oscillator. Control information is added to the sinusoidal wave by routing the wave through a phase inversion circuit a predetermined intervals according to a protocol. The resulting control signal is sent on a power line. The control signal is received using a crystal filter, decoded and converted to executable instructions for controlling a fan motor.

Abstract: In various embodiments, a method for controlling the operation of a transmitter circuit is provided, the method including: detecting a state of a message field within a data message to be sent by the transmitter circuit indicating a bit rate to be used for transmission by the transmitter circuit and switching the mode of operation of the transmitter circuit from a first data transmission mode to a second data transmission mode depending on the state of the message indication field, wherein in the first data transmission mode a first circuit configured to transmit data may be used and wherein in the second data transmission mode a second circuit configured to transmit data may be used. Further, a corresponding controlling circuit is provided.

Abstract: A switching unit comprises a COordinate Rotation DIgital Computer (CORDIC) unit configured to estimate a maximum phase difference between a phase of the GFSK modulated signal to be switched and a phase of the QPSK modulated signal after switch; a timing unit communicatively coupled to the CORDIC unit and configured to generate adaptive steps according to a switch time and the estimated maximum phase difference, wherein the CORDIC is further configured to generated an adjusted GFSK modulated signal by adjusting a phase of the GFSK modulated signal to be switched according to the estimated maximum phase difference and the adaptive steps.

Abstract: Systems and methods for transpositional modulation and demodulation are provided. One such method for generating a signal includes the steps of providing a look-up table having a plurality of quarter-cycle waveforms, each of said quarter-cycle waveforms associated with a respective input level; receiving an input signal; and outputting quarter-cycle waveforms associated with levels of the received input signal. Systems for transpositional modulation are also provided. One such system for generating a signal includes a look-up table having a plurality of quarter-cycle waveforms. Each of the quarter-cycle waveforms are associated with a respective input level, and the look-up table is configured to receive an input signal, and output quarter-cycle waveforms associated with levels of the received input signal.

Abstract: A transmitting apparatus groups a data bit sequence to groups each formed of a predetermined number of bits, modulates predetermined bits of one of groups through a frequency shift keying (FSK) modulation method, non-continuously aligns the FSK modulation signals, and transmits the non-continuous FSK modulation signals.

Abstract: A system and method for securing wireless communications are provided. A method for secure communications by a first user includes estimating a channel between the first user and a second user based on a pilot signal transmitted by the second user, determining a first threshold and a second threshold based on the estimate of channel, selecting a first subset of channel estimates, signaling the first subset of channel estimates to the second user, receiving a second subset of channel estimates from the second user, for each channel estimate in the second subset of channel estimates, quantizing the channel estimate based on a relationship between a gain of the channel estimate and the first threshold and the second threshold, generating a first secret key based on quantized channel estimates, verifying that the first secret key matches a second secret key generated by the second user, and transmitting information to the second user.

Abstract: An apparatus is used for modulation classification of unknown input signal in a wireless communication system. The apparatus includes a signal classification unit configured to classify the input signal into a PSK signal and an FSK signal and a modulation index decision unit configured to decide a modulation index for the PSK signal and the FSK signal classified by the signal classification unit.

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

Abstract: A coherent or a noncoherent transmission mode is automatically selected for a transmission on the basis of an estimated Doppler frequency shift due to a motion of a mobile terminal. A coherent mode is selected if a pilot signal overhead is not excessive to uniquely characterize a Doppler frequency shift, as at lower carrier frequency times relative velocity products. A noncoherent mode is selected if a pilot signal overhead would be excessive to uniquely characterize a Doppler frequency shift at higher carrier frequency times relative velocity products. Both the coherent and noncoherent modes have respective advantages for their respective carrier frequency time relative velocity regimes.

Abstract: The radio transmitting apparatus includes a first initial phase value setting circuit that sets, in the first modulator, an initial value of the phase of the first modulated signal, which is a value at the start of the modulation according to the first modulation scheme. The radio transmitting apparatus includes a second initial phase value setting circuit that sets, in the second modulator, the phase stored in the phase storing circuit as an initial value of the phase of the second modulated signal, which is a value at the start of the modulation according to the second modulation scheme. The radio transmitting apparatus includes a signal gathering circuit that selects and outputs the first modulated signal output from the first modulator and then selects and outputs the second modulated signal output from the second modulator.

Abstract: A method and apparatus for transmitting a sequence in a wireless communication system is provided. A transmitter generates a block sequence comprising a first sub-block sequence and a second sub-block sequence, generates a phase modulated block sequence by performing phase modulation on the block sequence, maps the phase modulated block sequence to a plurality of sub-blocks, and transmits the phase modulated block sequence mapped to the plurality of sub-blocks.

Abstract: A modulator performs data processing operations such as interpolation and fractional delay adjustment on amplitude and/or phase data by performing shift operations in lieu of multiplication operations. In selected embodiments, the modulator samples input data at a first rate, processes the sampled input data using the first rate, and then interpolates the processed data to produce interpolated data. The modulator then samples the interpolated data at a second rate higher than the first rate and generates output data at the second rate.

Abstract: A multi-class multimedia broadcast/multicast service (MBMS) system includes a transmitter and at least one receiver. The transmitter transmits N primary signals by N primary channels and an auxiliary signal by an auxiliary channel, wherein a resolution of the auxiliary signal is identical to the highest resolution of the N primary signals and the constellation mappings of the auxiliary signal and the primary signal with the highest resolution among said N primary signals on the corresponding modulation constellations are coupled. The receiver couples the primary signal with the corresponding auxiliary/virtual auxiliary signal to obtain a lower-resolution virtual auxiliary signal, which can also be coupled with the primary signal having the same resolution. Therefore, receiving quality of each resolution is improved by combining the primary signal and the corresponding auxiliary/virtual auxiliary signal.

Abstract: Methods and systems are disclosed herein for discriminating phase-shift-key (PSK) modulated signals from frequency-shift-key (FSK) modulated signals in received signal streams. First, a bit frequency analysis is applied to a digital signal stream representing the received signal stream. The bit frequency analysis computes bit frequencies for bit segments within the digital signal stream. These bit frequencies are then summed in an array to form a bit frequency histogram. Second, a bit phase analysis is applied to the digital signal stream. The bit phase analysis computes bit phases for bit segments within the digital signal stream. These bit phases are then summed in an array to form a bit phase histogram. Spikes within the bit frequency and bit phase histograms can be used to determine whether the received signal stream includes FSK or PSK signals. An enhanced bit phase analysis can also used, if needed.

Abstract: A unified filter bank for performing signal conversions may include an interface that receives signal conversion commands in relation to multiple types of compressed audio bitstreams. The unified filter bank may also include a reconfigurable transform component that performs a transform as part of signal conversion for the multiple types of compressed audio bitstreams. The unified filter bank may also include complementary modules that perform complementary processing as part of the signal conversion for the multiple types of compressed audio bitstreams. The unified filter bank may also include an interface command controller that controls the configuration of the reconfigurable transform component and the complementary modules.

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: Certain embodiments provide a system for recovering data from at least one signal. The system can include an analog-to-digital converter (ADC) and in-phase/quadrature (IQ) generator component that can sample a signal recovered from a communication medium to generate a first signal sample and a second signal sample. A Fast Fourier Transform (FFT) component can process the first signal sample to generate a first signal phase and process the second signal sample to generate a second signal phase. A phase difference calculation component can determine a phase difference between the first signal phase and the second signal phase, determine a bit value represented by the signal based on the phase difference, and output the bit value to an end device coupled to the phase difference calculation component.

Abstract: A “unified” modulator for multiple modulation schemes (e.g., GMSK and 8PSK) is described. The waveform for each modulation scheme is generated based on a set of one or more pulse shaping functions. The waveforms for all supported modulation schemes may be generated based on a composite set of all the different pulse shaping functions. The unified modulator includes a filter for each pulse shaping function in the composite set. To generate the waveform for a selected modulation scheme, the set of one or more filters for this modulation scheme is enabled and all other filters are disabled. The outputs from all enabled filters are summed to generate a modulator output. When switching between modulation schemes, a smooth transition may be obtained by (1) providing a suitable data pattern for each filter to be enabled or disabled and (2) generating symbols for the new modulation scheme with an appropriate initial phase.

Abstract: A modulator performs data processing operations such as interpolation and fractional delay adjustment on amplitude and/or phase data by performing shift operations in lieu of multiplication operations. In selected embodiments, the modulator samples input data at a first rate, processes the sampled input data using the first rate, and then interpolates the processed data to produce interpolated data. The modulator then samples the interpolated data at a second rate higher than the first rate and generates output data at the second rate.

Abstract: A system and method for remote activation of a device includes, in one embodiment, transmitting a command message according to a first modulation, and transmitting a signal representing the command message for the device according to a second modulation. The signal representing the command message transmitted according to the second modulation may be transmitted within the command message transmitted according to the first modulation.

Abstract: An apparatus for demodulating an analogue input signal comprises a hard limiter stage (4) for converting the signal to a two level signal. A digital down converter/low pass filter stage (6) converts the signal to a base band signal, and a symbol synchronization stage (8) extracts symbol timing. An instantaneous phase detector (10) calculates the instantaneous phase of the one or more symbols associated with the input signal. If the input signal has been modulated according to a pi/4DQPSK, pi/2DBPSK, GMSK, or a GFSK modulation scheme, a differential detector (12) determines a difference in the phase between adjacent symbols, a coarse frequency offset compensation stage (14) applies a compensation signal to compensate for frequency offset, and a frequency offset estimation stage (16) updates this compensation signal. A demapper (18) generates a demodulated output signal after compensation by the frequency offset compensation stage.

Abstract: The present invention provides a method, receiver and transmitter for use in a SDAR system. The method involves generating a first modulated signal based on first input data. Additional modulation is superimposed on the first modulated signal based on additional input data, being spread across a plurality of symbols in the first modulated signal in a predetermined pattern to generate a modified signal which is then transmitted. The modified signal is decoded by performing a first demodulation of the first modulated signal then additional demodulation is performed to obtain additional input data. The superimposing step uses a plurality of offset sequence values to add the additional modulation to the first modulated signal. The offset sequence may appear as a pseudo-random distribution of offset sequence values, and may include at least one zero offset value.

Abstract: Modulator system (1) comprising modulators (2, 3, 4) for modulating input signals (A) according to different modulation schemes (8PSK, GMSK) cause discontinuities in the output signals (F) when switching between the schemes. By providing the modulator systems (1) with compensators (13, 22-26) for compensating amplitudes/phases of the output signals (F) of the modulator system (1) for discontinuities, these discontinuities resulting from modulation scheme changes are reduced to a large extent. This may be done before/after the pulse shapers (11, 21). The compensators (13, 22-26) comprise multipliers for multiplying pulse shaped modulated signals with complex valued waveforms (E), or for multiplying modulated signals with waveforms (S, T), or for multiplying complex valued signals (B, C, D) with complex valued phase offsets (X, Y, Z), which complex valued signals (B, C, D) are to be multiplied with mapped input signals.

Abstract: A frequency and phase control apparatus includes an analog/digital conversion section for converting a reproduction signal into a multiple bit digital signal based on a clock signal; a maximum likelihood decoding section for converting the multiple bit digital signal into a binary signal; a pattern detection section for detecting a pattern of the binary signal; and a determination section for determining whether or not the multiple bit digital signal and the clock signal are in synchronization with each other based on the detection result. When the determination result of the determination section indicates that the multiple bit digital signal and the clock signal are in synchronization with each other, the maximum likelihood decoding section generates a binary signal based on a first state transition rule; otherwise, the maximum likelihood decoding section generates a binary signal based on a second state transition rule.

Abstract: The system and method enable simpler analog processing in a transmitter by reducing the number of bits in a digital signal through delta sigma modulation. Selection of current sources in a digital to analog converter of the transmitter is done using a randomization circuit.

Abstract: Repetitive synchronized signal events may be detected in received raw signal data that contains a signal. The type of signal, element length (or minimum interval) and/or other characteristics of such repetitive synchronized signal events may also be optionally determined. The disclosed methods and systems may be implemented for processing signals in real time as part of a receiver or transceiver system, or may be implemented by one or more computer processing components that are configured to process stored raw signal data or signal data received from another source, such as across a computer network.

Abstract: A radio transmitter within a transceiver includes a digital processor and analog circuitry for modulating and transmitting an outgoing digital signal in multiple modes of operation. The digital processor digitally modulates the outgoing digital signal to produce one of a constant envelope modulated digital signal and a variable envelope modulated digital signal based on the particular modulation scheme being used to modulate the outgoing digital signal. In addition, the digital processor filters the outgoing digital signal using filter values selected based on the signal bandwidth of the outgoing digital signal. The analog circuitry converts digital envelope and phase signals of the modulated digital signal to analog envelope and phase signals, and up-converts the analog phase signal from an IF signal to an RF signal, using a loop filter that is programmable based on the signal bandwidth of the outgoing digital signal.

Abstract: A convolutional decoder for a wired or wireless receiver receiving an encoded datastream. The branch and path metric components compute branch and path metrics for the encoded datastream stream. The traceback unit couples to the path metric component to trace in each traceback interval a single path through the path metrics to determine correction factors for decoding at least two corresponding successive sub-symbols/symbols from the encoded datastream in each traceback interval.

Abstract: Apparatus, and an associated method, for forming a space-generated multilevel coding scheme for a radio communication system. Two or more modulators are positioned at a sending station. The modulators modulate, pursuant to separate modulation schemes, data that is to be communicated by the sending station. The modulation schemes are lower-order modulation schemes. The modulated data is communicated to a receiving station, and detected at a least single receive antenna. The modulated symbols formed by the separate modulators are superimposed theretogether and form symbols of a higher order modulation scheme.

Abstract: A receiver includes an I-Q demodulator (135) responsive to the I and Q components carried on a first frequency signal line (132). A demodulator frequency generator (275) generates a demodulating signal to extract the carried I and Q components. A phase adjustment circuit (105) makes the demodulating signal substantially in phase with the first frequency signal. A transition detector (445) generates a state transition signal in response to a change of state of at least one of the I and Q signals. A peak detector (460) generates a peak detected signal in response to occurrence of a peak amplitude of at least one of the I and Q signals. A clock generator (470) adjusts the phase of a symbol clock signal used to decode the I and Q components in response to the state transition signal and peak detected signal.

Abstract: A sinusoidal RF carrier is modulated for the transmission of digital binary data streams through the amplitude suppression of carrier wavelets. These wavelets are defined between zero crossover positions representing zero energy locations. This modulation is accomplished when the carrier is slightly amplitude modulated with a modulation signal that is equal in frequency to the carrier itself and the modulation always begins or ends upon the exact zero voltage crossing point of the RF cycle phase. The modulation is applied as a slight shift of the amplitude of any single cycle, each cycle representing a single bit of data. A single cycle of RF will either represent a “1” or “0” depending upon the amplitude of the cycle, relative to other adjacent cycles in the same carrier.

Abstract: A FSK demodulation system of the present invention has a means for comparing two preset values across 0, a positive side level shift amount and a negative side level shift amount, with an inputted amplitude level; and a demodulation means for performing demodulation based on the comparison result.

Abstract: Based on changing reception conditions, a wireless receiver adapts its demodulation method during active communications. Phase errors detected in the received signal indicate current reception conditions, and, optionally, received signal strength serves as an additional indicator. The receiver supports operation with fully coherent, fully non-coherent, and partially coherent demodulation. The receiver determines a demodulation quality indicator based on the phase error signal. The value of the demodulation quality indicator increases with increasing phase error. When the demodulation quality indicator is below a first defined threshold, the receiver operates with fully coherent demodulation. When the demodulation quality indicator is above a second defined threshold, the receiver operates with fully non-coherent demodulation. For demodulation quality indicator values between the first and second defined thresholds, the receiver operates with partially coherent demodulation.

Abstract: An equalizer providing a filtered signal to a data decision unit calculates an amplitude error signal by comparing the filtered signal with the data signal output from the data decision unit, and calculates a squared envelope error signal from the filtered signal. These two error signals are separately weighted according to the absolute value of the amplitude error, the weight of the amplitude error signal decreasing and the weight of the squared envelope error signal increasing as the absolute value of the amplitude error increases. The weighted amplitude error signal and weighted squared envelope error signal are added to obtain an error signal used in updating filter coefficients in the equalizer. Rapid convergence of the filter coefficients is obtained, with small residual error.

Abstract: A system for communicating signals between a transmitter and a receiver using digital modulation techniques is provided. This invention is particularly adapted to meet the requirements of power line communication. In one preferred embodiment of this invention the modulation technique is differential binary phase shift key modulation. This system provides a low cost, simple delay and multiply process for the modulation and demodulation of data. This system lends itself to an ASIC implementation, thereby further reducing the cost of the system while improving the reliability of the system in a noisy environment.

Abstract: A method for phase encoding DPSK and N-PSK which maintains phase continuity and which does not require any reference symbols when using N-PSK. A sequence of known DPSK phases are encoded with respect to an initial phase. The N-PSK phases are then all offset by this same initial phase. The known DPSK phases can be used at a receiver to determine a sum consisting of the initial phase and any further phase shift introduced by the channel, and this sum is used to decode the unknown N-PSK phases. The method is more generally applicable to any case where a switch between a phase encoding method which requires an absolute phase reference and a phase encoding method which does not have an absolute phase reference is to be implemented on a single carrier or channel.

Abstract: A method 1100 and apparatus 1200 utilizing unbalanced modulation for providing users in a communication system with different amounts of effective communication energy according to their individual communication environments. A user's communication energy needs are determined based on conditions such as weather, signal-to-noise ratio, and cell location. Signals destined for a user are modulated according to the determined needs of the user. A signal destined for a user operating in a relatively friendly communication environment is modulated with less effective energy than a signal destined for a user operating in a relatively hostile communication environment.

Abstract: A radio receiver is adapted to receive radio signals in at least two frequency bands, in which the radio signals are modulated by information signals. The radio receiver includes a device for down-converting a received radio signal to an intermediate frequency signal by using a local oscillator, and a demodulating device for recovering the information signals from the intermediate frequency signal. The frequency of the local oscillator is selected so that the frequencies of at least one of the frequency bands are above the frequency of the local oscillator, and the frequencies of at least one of the frequency bands are below the frequency of the local oscillator.

Abstract: A method for increasing data rates within a modulated signal is disclosed. Initially, a first and second bit streams are interleaved together to form an interleaved output bit stream. The interleaved output bit stream is modulated in a manner such that upon demodulation of the interleaved output bit stream according to an FSK modulation scheme only the first bit stream is recovered, and upon demodulation of the interleaved output bit stream according to a second modulation scheme, both the first and second bit streams are recovered.

Abstract: A method and apparatus for phase encoding and decoding a CPM spread spectrum signal. A transmitter divides a data stream into a data symbol portion and an associated phase information portion. The data symbol portion is used to select one of a plurality of spread spectrum codes for transmission from a symbol table. The phase information portion is used to differentially phase encode the data symbol prior to transmission. The transmitter divides the phase encoded spread spectrum codes into a plurality of data streams (such as I and Q data streams), independently modulates the I and Q data streams using CPM or a related technique, and superposes the plurality of resultants for transmission. A receiver receives the superposed spread spectrum signal and simultaneously attempts to correlate for a plurality of chip sequences (such as I and Q chip sequences), and derives a real correlation signal and an imaginary correlation signal.

Abstract: An integrated circuit chip set is provided for use in a radio communication system in which a modulated digital input signal is processed for transmission and a modulated signal received from an antenna is processed to provide an output signal, wherein the modulation of the signals is either QPSK or FSK and the signal transmission and reception is by either TDD or FDD.

Abstract: A multiple-modulation communication system includes a transmitter that modulates and transmits communication signals modulated by a first modulation technique and communication signals modulated by a second modulation technique. The first modulation technique and the second modulation technique are different. The communication system also includes a receiver capable of receiving the communication signals modulated by the first modulation technique and the communication signals modulated by the second modulation technique and demodulating the communication signals.

Abstract: Data are transmitted using multiple carriers modulated by quadrature amplitude modulation. In general, the carriers carry different numbers of bits, to exploit the fact that the properties of a transmission path are more favorable to carriers at some frequencies than to those at others. The bit allocation process is made closer to optimum by permitting allocation of a non-integer number of bits to a carrier. Input bits are grouped for several carriers and this binary representation is converted to a number representation in which the base of each digit corresponds to the number of points in the QAM constellation for a respective carrier (or to this number divided by a power of two).

Abstract: The disclosure relates to methods and apparatus for separating radio signals arriving from different directions and for multiplexing signals intended for receivers dispersed in different directions. The methods and apparatus employ a plurality of antennas with spacing and individual feedline characteristics designed so that a modulation is imparted to each of a plurality of incident signals, for receiving antennas, and radiated signals for transmitting antennas, the modulation level of each signal being determined by the direction of propagation of the signal and by the spacing between antenna pairs. Accordingly, the orientation of lines connecting pairs of antennas as well as the spacing between antennas are set to inhibit the modulation in a particular direction, or to strip a particular modulation off a signal incident from a selected direction.

Abstract: A synchronizing signal generating apparatus generates a synchronizing signal from digital data in which a synchronizing signal formed of a fixed data pattern having a predetermined bit number is inserted at a predetermined time interval L.