Abstract: A wireless power transfer system is provided having a wireless transmission system with an input to receive input power from an input power source, a transmission antenna configured to couple with a receiver antenna associated with a wireless receiver system in a peripheral device, and a transmission controller configured to generate AC wireless signals including wireless power signals and wireless data signals. The transmission controller is further configured to derive a coupling factor based on coupling data sent from the wireless receiver system to the wireless transmission system, generate an update frequency based on the derived coupling factor, and transmit the update frequency to the wireless receiver system in the peripheral device, whereby the peripheral device provides coupling data to the wireless transmission system based on the update frequency.

Abstract: The subject of the invention Is a method of processing a signal of a passive RFID chip (1) with a reader (2) in order to amplify the useful signal. A method of processing a signal of a passive RFID chip (1) with a reader (2) comprising an antenna (3), an operational amplifier (4), an AD converter (5) and a first DA converter (6) and a second DA converter (7) or a source of constant voltage consists of steps of transmitting the source signal of the antenna (3), receiving the source signal of the antenna (3) by the RFID chip (1), transmitting the RFID chip (1) signal and receiving the RFID chip (1) signal by the antenna (3), wherein the received RFID chip (1) signal and the output of the first DA converter (6) is fed to the inverting input of the operational amplifier (4) and the output of the second DA converter (7) or the output of the source of constant voltage is fed to the non-inverting input of the operational amplifier (4).

Abstract: A sensor degradation detection and remediation system includes one or more sensors configured to collect image data from an environment. A combination of techniques may be used to detect degradations within regions of the image data captured by a sensor, including one or more of determining a level of the visual consistency between the associated image regions captured by different sensors, determining a level of opaqueness of the image regions, and/or measuring temporal movement of the image regions captured by a sensor over a period of time. Operations of a vehicle or other system may be controlled based at least in part on the detection of degradations of the image data captured by the sensors, including automated cleaning of a sensor surface, reducing a level of reliance on the image data received from the sensor, and/or changing a direction of travel of the vehicle.

Abstract: A motor driving apparatus includes an amplifier receiving, from a detector, a sine wave shaped signal detected in response to rotation of a motor, and amplifying the signal with a set amplification factor, an A/D converter for performing digital conversion by sampling the signal amplified by the amplifier at a sampling timing in a predetermined cycle, an amplification factor setting part for changing setting of the amplification factor of the amplifier, and an amplification factor set timing command part for issuing a command with respect to a timing for changing the setting of the amplification factor by the amplification factor setting part. The amplification factor set timing command part issues the command with respect to the timing so that a waveform stabilizing period until distortion in a waveform of the signal occurring when the amplification factor setting part changes the setting is stabilized does not overlap with the sampling timing.

Abstract: A circuit for demodulating an input signal is described. The circuit may be configured to demodulate signals modulated with amplitude-based modulation schemes, such as amplitude shift keying (ASK). The demodulator may comprise a clock extractor configured to generate a clock signal in response to receiving an amplitude-modulated input signal, a phase shifter configured to generate a sampling signal by phase-shifting the clock signal by approximately ?/2, and a sampler configured to sample the input signal in correspondence to one or more edges (such as one or more falling edges) of the sampling signal. In this way, the amplitude-modulated input signal may be sampled at its peak, or at least near its peak, thus ensuring high signal fidelity.

Abstract: A circuit for demodulating an input signal is described. The circuit may be configured to demodulate signals modulated with amplitude-based modulation schemes, such as amplitude shift keying (ASK), such that information is encoded in the amplitude of the signals. The circuit may comprise an amplitude detector for extracting the envelope of a received amplitude-modulated signal, a phase/frequency detector for detecting phase and/or frequency shifts, and a selector configured to select one between the output of the amplitude detector and the output of the phase/frequency detector. The selector may be controlled by a control circuit including a delay unit.

Abstract: A power supply circuit can be configured to generate a supply voltage that provides power to the apparatus. A signal generation circuit can be configured to generate a radio frequency (RF) charging signal. An amplification circuit can be configured to amplify the RF charging signal using the supply voltage and to present the amplified charging signal to a power transmitting coil for transmission of wireless power to a remote device. A communication circuit can be configured to detect amplitude variations in the RF charging signal; detect variations in a voltage level of the supply voltage; adjust the detected amplitude variations in the RF charging signal to compensate for detected variations in a voltage level; and decode data represented by the amplitude variations in the RF charging signal based upon the adjusted amplitude variations.

Abstract: In accordance with an embodiment, a method includes determining an amplitude of an input signal provided by a capacitive signal source, compressing the input signal in an analog domain to form a compressed analog signal based on the determined amplitude, converting the compressed analog signal to a compressed digital signal, and decompressing the digital signal in a digital domain to form a decompressed digital signal. In an embodiment, compressing the analog signal includes adjusting a first gain of an amplifier coupled to the capacitive signal source, and decompressing the digital signal comprises adjusting a second gain of a digital processing block.

Abstract: A vector sum circuit for producing a radio frequency (RF) output at a selectable phase offset includes an RF input configured to receive a differential pair RF input. A quadrature network produces an additional pair of RF inputs whose phase is advanced 90 degrees (90°) with reference to the first differential pair RF input, thereby producing four RF input signals offset at 0°, 90°, 180° and 270°. For each RF input signal, a set of three cascodes, having a plurality of NPN transistors and each emitter being commonly connected to an RF input. The first cascode steers current to a first output node, the second cascode steers current to a second output node and the third cascode shunts current to the voltage rail. By selectively steering current from the quadrature RF inputs to a selected output, an output signal having a desired phase shift is achieved.

Abstract: An object is to provide a demodulation circuit having a sufficient demodulation ability. Another object is to provide an RFID tag which uses a demodulation circuit having a sufficient demodulation ability. A material which enables a reverse current to be small enough, for example, an oxide semiconductor material, which is a wide bandgap semiconductor, is used in part of a transistor included in a demodulation circuit. By using the semiconductor material which enables a reverse current of a transistor to be small enough, a sufficient demodulation ability can be secured even when an electromagnetic wave having a high amplitude is received.

Abstract: A device receives ASK signals by using an ASK signal receiving circuit that is different from an ASK signal receiving circuit for R/W mode, when an NFC-enabled semiconductor device operates in a mode other than the R/W mode. An ASK signal receiving circuit for 100% ASK is provided on the side of a pair of transmitting terminals. This arrangement eliminates the influence of an ESD provided within an ASK signal receiving circuit for 10% ASK coupled to a pair of receiving terminals. There is no need for management of threshold values that are different according to type of ASK and it is possible to support different modulation schemes by a smaller circuit configuration.

Abstract: Disclosed herein is a demodulator, including: a splitting/matching section for carrying out a matching process of making the amplitude and phase of a first modulated signal match respectively the amplitude and phase of a second modulated signal; and a demodulation section for generating a demodulated signal on the basis of the first modulated signal and the second modulated signal, which have been subjected to the matching process carried out by the splitting/matching section, wherein the splitting/matching section has a splitting section, a first matching section, and a second matching section, the first circuit-element constants determining the first input impedance of the first matching section and the second circuit-element constants determining the second input impedance of the second matching section are set at values determined in advance in order to make the first input impedance equal to the second input impedance.

Abstract: The envelope detector for detecting an envelope of a digital modulation signal in accordance with an embodiment of the present invention, includes: a mixer configured to receive the digital modulation signal and output a square signal squaring the digital modulation signal when being applied with bias voltage; a bias voltage applying unit configured to apply the bias voltage to the mixer; and a DC blocking capacitor configured to be connected to the mixer to block DC component included in the square signal. In accordance with the embodiment of the present invention, it is possible to provide the envelope detector having the simple structure while having the good receiving sensitivity and the wide dynamic range characteristics and detect the envelope of the modulated signal without transmitting the carrier signal in the transmitter and generating the separate signal in the receiver, thereby saving the costs consumed to implement the transceiver.

Abstract: A BASK demodulator includes a signal modifying circuit and a low pass filter (LPF) that couples an amplifier to an output of the modifying circuit. The modifying circuit includes a signal scaling circuit, a rectifying circuit and an AC coupling circuit. A signal shaping circuit couples an output of the amplifier to an output of the demodulator. The signal scaling circuit scales an input BASK modulated signal to provide an unclipped scaled and biased alternating signal that alternates about a bias voltage at a minimum carrier frequency. The rectifying circuit rectifies the unclipped signal to provide a partially rectified signal that is decoupled by the AC coupling circuit to provide a clipped scaled and biased alternating signal. The LPF removes the signal from the clipped scaled and biased alternating signal to provide a demodulated signal, which then is amplified by the amplifier and shaped by the shaping circuit.

Abstract: The invention relates to modulation and demodulation circuits, such as envelope detectors used to demodulate amplitude-modulated (AM) signals. By coupling an analog circuit to a port of a digital component, a compact envelope detector can be obtained, which achieves demodulation of AM signals for direct coupling into a digital input port. Accordingly, a compact envelope detector may be used in the data receiving part of a sealed device requiring post-manufacturing data transfer, in combination with additional components that provide electromagnetic coupling, such as inductive, capacitive, or radiative. An example of such a device is a credit card sized authentication token.

Abstract: A dynamic adjusting RFID demodulator circuit includes an envelope detector having an input for receiving a modulated RF signal, a fixed reference generator coupled to the input of an RC filter, an RF level dependent signal path adding to the fixed reference level at higher RF energy levels, a comparator having a first input coupled to an output of the envelope detector, a second input coupled to an output of the RC filter, and an output for providing a data output signal.

Abstract: In accordance with an embodiment, a method includes determining an amplitude of an input signal provided by a capacitive signal source, compressing the input signal in an analog domain to form a compressed analog signal based on the determined amplitude, converting the compressed analog signal to a compressed digital signal, and decompressing the digital signal in a digital domain to form a decompressed digital signal. In an embodiment, compressing the analog signal includes adjusting a first gain of an amplifier coupled to the capacitive signal source, and decompressing the digital signal comprises adjusting a second gain of a digital processing block.

Abstract: A modulator, a demodulator and a modulator-demodulator are provided. A modulator includes a first intermediate signal processing path adapted to route a first intermediate signal; a second intermediate signal processing path adapted to route a second intermediate signal; a first amplifier coupled into the first intermediate signal processing path; a second amplifier coupled into the second intermediate signal processing path; and a chopper circuit coupled into the first intermediate signal processing path; wherein the chopper circuit is adapted to process the first intermediate signal in dependence on first baseband data; wherein the first amplifier is adapted to amplify the first intermediate signal processed by the chopper circuit in dependence on second baseband data; and wherein the second amplifier is adapted to amplify the second intermediate signal in dependence on the second baseband data.

Abstract: An object is to provide a demodulation circuit having a sufficient demodulation ability. Another object is to provide an RFID tag which uses a demodulation circuit having a sufficient demodulation ability. A material which enables a reverse current to be small enough, for example, an oxide semiconductor material, which is a wide bandgap semiconductor, is used in part of a transistor included in a demodulation circuit. By using the semiconductor material which enables a reverse current of a transistor to be small enough, a sufficient demodulation ability can be secured even when an electromagnetic wave having a high amplitude is received.

Abstract: In conventional radio frequency (RF) systems, transmitters will usually convert baseband signals to RF so as to be transmitted. As part of the conversion process, the transmitters will perform digital predistortion (DPD), which uses feedback from a power amplifier. However, there are usually mismatches between the in-phase (I) and quadrature (Q) paths within with feedback loop. Traditional IQ correction filters were ineffective at providing adequate compensation for these mismatches, but here a filter is provided that provides adequate out-of-band compensation by use of frequency selectivity.

Abstract: A receiving system and a method of processing broadcast signals in the receiving system are disclosed. The receiving system includes a tuner, a known sequence detector, a carrier recovery unit, a baseband processor, and a channel equalizer. The tuner receives a broadcast signal of a passband including a data group. Herein, the data group comprises mobile service data, a plurality of known data sequences, and signaling data. The known sequence detector estimates an initial frequency offset and detects a position of each known data sequence based on the known data sequence having the first data pattern. The carrier recovery unit acquires an initial frequency synchronization using the initial frequency offset estimated by the known sequence detector and estimates a residual frequency offset based upon the known data sequences having the second data pattern so as to perform carrier recovery.

Abstract: An object is to provide a demodulation circuit having a sufficient demodulation ability. Another object is to provide an RFID tag which uses a demodulation circuit having a sufficient demodulation ability. A material which enables a reverse current to be small enough, for example, an oxide semiconductor material, which is a wide bandgap semiconductor, is used in part of a transistor included in a demodulation circuit. By using the semiconductor material which enables a reverse current of a transistor to be small enough, a sufficient demodulation ability can be secured even when an electromagnetic wave having a high amplitude is received.

Abstract: An ASK demodulator comprises a rectification circuit which receives and rectifies an ASK signal to generate a rectified current; an active load circuit is coupled to the rectification circuit and receives the rectified current and present an impedance which is inversely proportional to at least a part of the rectified current when a frequency of a base band signal meets a preset condition; a comparator is coupled to the rectification circuit and the active load circuit and receives a reference voltage and a voltage generated based on, at least in part, the rectified current and the impedance, and compares the reference voltage and the generated voltage to generate a demodulated signal.

Abstract: An envelope detection apparatus dynamically controlled in response to an input signal and an envelope detection method thereof are provided. The envelope detection apparatus includes an envelope detector configured to output an envelope of an input signal. The envelope detection apparatus further includes a detection band determination unit configured to determine a detection band based on the input signal. The envelope detection apparatus further includes a detection band controller configured to control a detection band of the envelope detector based on the determined detection band.

Abstract: This analog electronic circuit (2) for processing a light signal (4), of the type comprising: a photodetector (6) adapted for producing an electric signal (8) from the light signal (4); a multiplier (12) adapted for multiplying the electric signal (8) with a reference signal (14) for obtaining a multiplied signal (16); and an integrator (18) adapted for integrating the multiplied signal (16) over at least one time interval, in order to obtain one integrated signal, is characterized in that it further comprises: an analog memory (24) adapted for storing the integrated signal in memory; and a computing unit adapted for estimating a time correlation of the light signal (4) from the integrated signal stored in memory.

Abstract: A new demodulator with low power consumption and high gain which is suitable for CMOS integration is provided. The demodulator makes use of a MOS configured in a “common-source” status so as to achieve a desirable gain.

Abstract: A dynamic adjusting RFID demodulator circuit includes an envelope detector having an input for receiving a modulated RF signal, a fixed reference generator coupled to the input of an RC filter, an RF level dependent signal path adding to the fixed reference level at higher RF energy levels, a comparator having a first input coupled to an output of the envelope detector, a second input coupled to an output of the RC filter, and an output for providing a data output signal.

Abstract: A binarization circuit includes a comparator that outputs a signal according to a differential voltage between the input and reference voltages. The first charging-discharging circuit generates a first voltage. The second charging-discharging circuit generates a second voltage. The control circuit compares the differential voltage with the threshold voltage, and switches between turn-on and turn-off of the second charging-discharging circuit based on a difference between the differential voltage and the threshold voltage. A sum of the reference and first voltages of the preceding clock is supplied to the comparator when the second charging-discharging circuit is turned off. A sum of the reference and the first and second voltages of the preceding clock is supplied to the comparator when the second charging-discharging circuit is turned on.

Abstract: A demodulator according to the present invention is the demodulator that demodulates a plurality of received symbols having different amplitude of carrier wave. The demodulator includes an amplitude value calculation unit that calculates a received symbol amplitude value by adding an absolute value of in-phase component and an absolute value of quadrature component determined from the amplitude of the carrier wave in the received symbol. Further, the demodulator includes a demodulation unit that detects a change of the received symbol amplitude value calculated by the amplitude value calculation unit, and demodulates the received symbol based on the detection result.

Abstract: A method of demodulating a signal on which is modulated, using a quadrature amplitude modulation scheme, a plurality of information symbols, the method including: determining at least one QAM detection threshold corresponding to one or more of said information symbols; and demodulating each information symbol on the basis of at least one respective QAM detection threshold.

Abstract: An object is to provide a demodulation circuit having a sufficient demodulation ability. Another object is to provide an RFID tag which uses a demodulation circuit having a sufficient demodulation ability. A material which enables a reverse current to be small enough, for example, an oxide semiconductor material, which is a wide bandgap semiconductor, is used in part of a transistor included in a demodulation circuit. By using the semiconductor material which enables a reverse current of a transistor to be small enough, a sufficient demodulation ability can be secured even when an electromagnetic wave having a high amplitude is received.

Abstract: The present invention relates to a modulation and demodulation method of minimizing an error rate and applying it to a differential operation modulo 4. A modulation apparatus includes a Gray coding circuit 101 to which data of (2n+1) bits are inputted (where “n” is an integer more than 1) and which encodes 2 bits of an input signal of (2n+1) bits to a Gray code as a signal for allowing four quadrants to be identified, an encoding circuit 102 that encodes 3 bits of the input signal of (2n+1) bits as a signal indicating any one of eight subgroups provided in each of the four quadrants so that an average Hamming distance between adjacent subgroups within its quadrant becomes a minimum, and a mapping circuit 104 that maps binary data encoded by the Gray coding circuit 101 and the encoding circuit 102 on the four quadrants.

Abstract: An RFID transponder having an antenna for receiving an RF signal including an amplitude modulated downlink data signal, and a demodulating stage coupled to the antenna for receiving a derived RF signal which is derived from the received RF signal. The demodulating stage has a first filter for extracting a field strength signal component from the derived RF signal and a second filter for extracting the modulated downlink data signal component from the derived RF signal. Further, a demodulator is coupled to the second filter to receive the modulated downlink signal for demodulating the modulated downlink data signal component and coupled to the first filter to receive the field strength signal such that the demodulator is adapted to vary a demodulation sensitivity parameter in response to the field strength signal.

Abstract: A semiconductor device is provided, which comprises a first demodulation circuit, a second demodulation circuit, a first bias circuit, a second bias circuit, a comparator, an analog buffer circuit, and a pulse detection circuit. An input portion of the pulse detection circuit is electrically connected to an output portion of the analog buffer circuit, a first output portion of the pulse detection circuit is electrically connected to an input portion of the first bias circuit, and a second output portion of the pulse detection circuit is electrically connected to an input portion of the second bias circuit.

Abstract: A demodulator for demodulating a modulated signal has a peak detector (206) with an input (100) coupled to receive the modulated signal and an output (207) to supply a peak detector output signal. The peak detector has a charge storer (314) coupled to the peak detector output so that the peak detector output signal is provided by a voltage across the charge storer (314) and a comparator (313) having a first comparator input coupled to the peak detector input to receive the modulated signal and a second comparator input coupled to the peak detector output to receive the peak detector output signal. The comparator (313) provides a comparison signal representing a comparison between the voltage of the modulated signal and the peak detector output signal.

Abstract: The invention relates to modulation and demodulation circuits, such as envelope detectors used to demodulate amplitude-modulated (AM) signals. By coupling an analog circuit to a port of a digital component, a compact envelope detector can be obtained, which achieves demodulation of AM signals for direct coupling into a digital input port. Accordingly, a compact envelope detector may be used in the data receiving part of a sealed device requiring post-manufacturing data transfer, in combination with additional components that provide electromagnetic coupling, such as inductive, capacitive, or radiative. An example of such a device is a credit card sized authentication token.

Abstract: Embodiments of the invention are concerned with correction of quadrature errors associated with digital communications systems, and in particular in a wireless transmit chain in which an up-converter and a down-converter both have a direct conversion architecture. One embodiment comprises a correction network for correcting a difference between a transmission characteristic of an in-phase signal path and a transmission characteristic of a quadrature signal path, said quadrature signal path being for the transmission of in-phase and quadrature parts of a signal and the signal comprising frequency components within a base band, wherein the correction network comprises an in-phase input port, a quadrature input port, an in-phase output port and a quadrature output port, wherein each input port is connected to each output port by a digital filter network, the digital filter network comprising a set of filter tap coefficients and configuration means for configuring values of said set of filter tap coefficients.

Abstract: The present invention shows a contactless chip card comprising a controllable demodulation unit for demodulating an amplitude-modulated carrier signal, a measuring unit for determining a degree of modulation of the modulated carrier signal, and a control unit for controlling the demodulation unit on the basis of the determined degree of modulation of the carrier signal.

Abstract: Provided is a test apparatus for testing a device under test that outputs, as an output signal, an amplitude-phase modulated signal having a level and a transition point phase selected from among a plurality of levels and a plurality of phases according to transmission data, the test apparatus comprising a comparing section that compares the output signal to a first comparison level, which is less than the expected level, before the expected phase, and compares the output signal to a second comparison level, which is greater than the expected level, and to a third comparison level, which is less than the expected level, after the expected phase; and a judging section that judges that the output signal matches the expected values on a condition that (i) the output signal is less than or equal to the first comparison level before the expected phase and (ii) the output signal is less than or equal to the second comparison level and greater than or equal to the third comparison level after the expected phase.

Abstract: The invention relates to the field of modulation and demodulation circuits, such as envelope detectors used to demodulate amplitude-modulated (AM) signals. By coupling an analog circuit to a port of a digital component, an envelope detector can be obtained, which achieves demodulation of AM signals for direct coupling into a digital input port. Accordingly, an envelope detector may be used in the data receiving part of a sealed device requiring post-manufacturing data transfer, in combination with additional components that provide electromagnetic coupling, such as inductive coupling, capacitive coupling, or radiative coupling. An example of such a device is a credit card sized authentication token.

Abstract: Signal processing circuit including a demodulator that receives a receive signal with signal edges, and outputs a demodulated receive signal with transitions from a first level to a second level or vice versa at signal edges of the receive signal, wherein points of time of the transitions depend on the steepnesses of the signal edges. The circuit also includes an edge evaluator that receives the receive signal, and outputs an evaluation signal which includes information about the steepnesses of the signal edges. The circuit also includes a signal generator that receives the output of the demodulator, receives the output of the edge evaluator, and outputs a corrected demodulated receive signal with transitions whose points of time are set with regard to the points of time of the transitions of the demodulated receive signal based on the evaluation signal in order to reduce influences of different steepnesses of the signal edges.

Abstract: A test signal is generated and supplied to a signal processing circuit for making frequency conversion. A signal outputted from the signal processing circuit is detected to generate a detected signal including a detected positive signal corresponding to the positive signal of the test signal and a detected negative signal corresponding to the negative signal. And the level of the detected positive signal and the level of the detected negative signal are compared to output the comparison result indicating which level is higher. Further, an offset correction signal for making a level difference between the detected positive signal and the detected negative signal within a preset permissible range is generated, based on the comparison result, and offset correction of the test signal or modulated signal supplied from the outside is made in accordance with the offset correction signal.

Abstract: A passive RFID transponder includes a coder and a modulator. The coder generates a digital coded data stream based on a digital data stream to be transmitted. The digital coded data stream includes an initialization bit sequence having a maximum data frequency of the digital coded data stream. Furthermore, the digital coded data stream changes its value at the latest after a predefined number of bits. The modulator modulates an amplitude of a carrier signal with the digital coded data stream to provide an amplitude-modulated coded signal.

Abstract: A demodulator is provided for demodulating an amplitude-modulated input signal defined by a carrier signal having a carrier frequency modulated by a modulating signal, the demodulator including an amplifier stage having a gain and structured to receive the amplitude-modulated input signal, and a gain control stage coupled to the amplifier stage and configured to vary the gain of the amplifier stage according to the carrier frequency of the carrier signal.

Abstract: The present invention relates to a demodulator for simultaneous multi-node receiving and a method therof; and, more particularly, a demodulator in a wireless communication system for receiving signals from multi nodes simultaneously and a method thereof. In accordance with the aspect of the present invention, there is provided a demodulator for simultaneous multi-node receiving which comprises: a clock generator for generating a pair of CW signals and a pair of demodulating modules, wherein the demodulating modules comprise a mixer for multiplying received signals and one of the CW signals, an integrator for integrating multiplied signal and data operating unit for calculating variation result of integrated signal at every certain symbol duration and deciding output data in accordance with the variation result.

Abstract: Disclosed herein is a demodulation apparatus including: an operation determination block configured to determine whether the demodulation apparatus operates as part of either a first device or a second device with which the demodulation apparatus communicates, the first device being configured to ASK-modulate and transmit data, the second device being configured to load-modulate and transmit data; and first and second demodulation control blocks.

Abstract: The present invention relates to a wire-bound transmission of data, as occurs, for example, between a sensor and a control unit. In order to save lines, both the supply voltage and the data signal to be transmitted are transmitted over the same line. The field of the present invention relates to the extraction of data signals from the supply voltage line.

Abstract: A demodulator according to the present invention is the demodulator that demodulates a plurality of received symbols having different amplitude of carrier wave. The demodulator includes an amplitude value calculation unit that calculates a received symbol amplitude value by adding an absolute value of in-phase component and an absolute value of quadrature component determined from the amplitude of the carrier wave in the received symbol. Further, the demodulator includes a demodulation unit that detects a change of the received symbol amplitude value calculated by the amplitude value calculation unit, and demodulates the received symbol based on the detection result.

Abstract: The determination of the signal modulation format for a channel is an important aspect of the operation of a signal receiver. A method (700) is described including the steps of receiving (710) a signal, comparing (720) a sample of the received signal to a first threshold value and a second threshold value, creating (720) a signal profile based on the comparison, and selecting (750) a modulation format for the received signal based on the signal profile. An apparatus (500) is also described including a ring counter (510) that receives a sample of an input signal, compares the sample to a first threshold value and a second threshold value, and creates a signal profile for the input signal, a signal profiler (550) that compares the signal profile for the input signal to at least two reference profiles, and a detector (560) that determines a modulation format for the input signal based on the comparison in the signal profiler (550).

Abstract: A demodulation apparatus that demodulates an amplitude-phase-modulated signal having a level and a transition phase selected from among a plurality of levels and a plurality of phases according to transmission data, comprising a clock recovering section that receives the amplitude-phase-modulated signal and recovers a clock signal synchronized with the amplitude-phase-modulated signal; an amplitude and phase detecting section that detects, with the clock signal as a reference, the level and the transition phase of the amplitude-phase-modulated signal; a data output section that outputs data corresponding to the level and the transition phase detected by the amplitude and phase detecting section; and a phase difference correcting section that outputs a correction signal for correcting an oscillation frequency of the clock signal output by the clock recovering section, according to the transition phase detected by the amplitude and phase detecting section.