Abstract: Apparatus and methods for enhancement of performance in polar modulators are described. In one implementation, an FM signal component is divided into a coarse FM signal and a residue FM signal to be applied to a VCO for generation of a modulation signal. The coarse FM signal may be proportional to a threshold value when the FM signal exceeds the threshold, while the residue FM signal may be proportional to the difference between the FM signal and coarse FM signal.

Abstract: A carrier leak compensating device (2) for adding compensation values to a received transmission signal, an analog quadrature modulator (4), a feedback device (5-7) for receiving and quadrature-detecting part of an output signal of the analog quadrature modulator and outputting a feedback signal in which the frequency of each carrier signal is the same as in the transmission signal, a carrier leak detecting device (800) for detecting an I-phase carrier leak and a Q-phase carrier leak on the basis of the difference between cumulative addition values of an amplitude/phase-adjusted feedback signal and the transmission signal, and a carrier leak compensation value controller (9) for updating the compensation values on the basis of the detected carrier leak. The number of samples for the amplitude/phase detection may be smaller than the number of cumulative addition samples.

Abstract: A method for tuning a digital compensation filter within a transmitter includes: obtaining at least one loop gain calibration result by performing loop gain calibration based upon signals of at least a portion of the transmitter, and obtaining at least one resistance-capacitance (RC) detection result by performing RC detection on the portion of the transmitter without individually measuring resistance values of resistors therein and capacitance values of capacitors therein, wherein the RC detection result corresponds to a detected value representing a product of a resistance value and a capacitance value, and the digital compensation filter includes a gain compensation module and an RC compensation module; and tuning the digital compensation filter by respectively inputting the loop gain calibration result and the RC detection result into the gain compensation module and the RC compensation module. An associated digital compensation filter and an associated calibration circuit are also provided.

Abstract: A modular power supply that can be adapted to receive and charge practically any type or number of portable electronic devices includes a power converter that receives an AC wall voltage and converts the wall voltage to DC bus voltage. Each charging module has a pair of conductive rails and magnets positioned around the exterior of the module. The power converter has a connector that is physically and electrically coupled to a charging module through a pair of magnets and conductive rails such that the DC bus voltage is applied to the conductive rails of the module. Each charging module has a dock that physically couples to a portable electronic device and supplies a charging voltage produced from the DC bus voltage to the device. Additional charging modules can be physically and electrically coupled together by simply placing the modules adjacent one another through the interaction of the module's conductive rails and magnets.

Abstract: A demodulation section 13 receives a TDMA-TDD based phase-modulated burst signal of mobile communications and demodulates the burst signal by a synchronous detection system (or a quasi-synchronous detection system). The demodulation section 13 includes a frequency deviation compensation section and a carrier recovery section each having a loop filter 14 with three or more stages of time constants. The time constants are switched by a selector switch 15 based on a control signal from a demodulation control section 16. This achieves quick pull-in and jitter after convergence is minimized, thereby allowing highly efficient performance of frequency deviation compensation, etc. that is required for synchronous detection (or quasi-synchronous detection) without increasing the size of circuit.

Abstract: A reconfigurable multimode transmitter is disclosed, operating in accordance with a two-step channel selection. The first step provides for a fine channel selection and upconversion of a desired channel to either positive or negative IF. The second step is a coarse channel selection and upconversion of a desired channel to the RF. The receiver and transmitter can be used in a transceiver.

Abstract: Provided are a PLL modulation circuit, a radio transmission device, and a radio communication device capable of maintaining a modulation accuracy for modulation of a wide band.

Abstract: A modulation circuit for use in a radiofrequency transmitter includes a local oscillator circuit configured to generate one or more local oscillator signals at a desired frequency and with a duty cycle at or about twenty-five percent, and a modulator configured to generate one or more modulated signals responsive to the one or more local oscillator signals and one or more baseband information signals. In at least one embodiment, the modulation circuit includes a modulator comprising a combined mixing and transconductance circuit that includes a transistor circuit for each baseband information signal serving as a modulation input to the modulator. Each transistor circuit comprises a first transistor driven by the baseband information signal and coupling a modulator output node to a corresponding transconductance element, and a second transistor driven by one of the one or more local oscillator signals and coupling the corresponding transconductance element to a signal ground node.

Abstract: A real-time/non-real-time/RF IC includes first and second baseband processing modules, an RF section, a wireline interface, and a bus structure. The first baseband processing module converts real-time outbound data into real-time outbound symbols and converts real-time inbound symbols into real-time inbound data. The second baseband processing module converts non-real-time outbound data into non-real-time outbound symbols and converts non-real-time inbound symbols into non-real-time inbound data. The RF section converts the real-time outbound symbols into real-time outbound RF signals, converts real-time inbound RF signals into the real-time inbound symbols, converts the non-real-time outbound symbols into non-real-time outbound RF signals, and converts non-real-time inbound RF signals into the non-real-time symbols. The wireline interface couples the non-real-time outbound data, the non-real-time inbound data, the real-time outbound data, and/or the real-time inbound data to an off-chip wireline connection.

Abstract: Systems and methods are provided for efficiently determining frequency estimates in a forward link only wireless receiver. In one embodiment, a method is provided to compute a one shot frequency estimate. The method includes representing an arc tangent function in a table that describes elements of the function and employing the arc tangent function to compute phase information for a wireless device.

Abstract: Methods, systems, and apparatuses, and combinations and sub-combinations thereof, for down-converting an electromagnetic (EM) signal are described herein. Briefly stated, in embodiments the invention operates by receiving an EM signal and recursively operating on approximate half cycles (½, 1½, 2½, etc.) of the carrier signal. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The invention accumulates the results of the recursive operations and uses the accumulated results to form a down-converted signal. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal.

Abstract: An FM signal transmitter has a processing module, a connecting module and an FM transmitting module. The connecting module is electronically connected to the processing module and has a Universal Serial Bus (USB) unit that is selectively connected to a computer and receives audio data from the computer, wherein the USB unit has a memory storing a preset USB class. The FM transmitting module is electronically connected to and controlled by the processing module to broadcast an FM signal corresponding to the audio data under a specific frequency. The computer may perform an audio filtering method to successively rewrite the preset USB class from USB-HID, USB-AUDIO and USB-HID so that the computer can transmit audio data excluding system generated sounds to the FM signal transmitter.

Abstract: A phase correction apparatus in a wireless transmitter includes a modulator for modulating a first carrier signal by an in-phase component and a quadrature-phase component of a first signal, a demodulator for demodulating a returned signal by a second carrier signal and generating a second signal including an in-phase component and an quadrature-phase component, a phase detector for detecting a phase error between the first signal and the second signal based on the in-phase components and the quadrature-phase components of the first and second signals, and a phase shifter group for performing a phase shift based on the phase error, the phase shifter group including a first phase shifter for performing a phase shift on any of the first signal, the second signal, the first carrier signal, and the second carrier signal and a second phase shifter for shifting a phase of the first signal.

Abstract: A phase corrector in a radio transmitter includes a quadrature modulator which modulates a first carrier signal by using an in-phase component and a quadrature component of a first signal, a quadrature demodulator which demodulates a feedback signal by using a second carrier signal to generate a second signal including an in-phase component and a quadrature component, a phase detector which detects a phase error between the first signal and the second signal based on the in-phase components and the quadrature components of the first signal and the second signal, and a phase shifter which performs phase shift of any one of the first signal, the second signal, the first carrier signal and the second carrier signal based on a sum value obtained by adding to the phase error a first phase amount varying on a time base in a given phase range.

Abstract: A phase correction apparatus in a wireless transmitter includes a modulator configured to modulate an in-phase component and a quadrature component of a first signal by a first carrier wave signal, a demodulator configured to demodulate a returned signal by a second carrier wave signal and generate a second signal that includes an in-phase component and a quadrature component, a phase detector configured to binarize the in-phase components and the quadrature components of the first and second signals according to signal levels, and detect a phase error between the first signal and the second signal based on combinations of the binarized signal components in the first signal and the second signal, and a phase shifter configured to phase-shift the first signal, the second signal, the first carrier wave signal, or the second carrier wave signal, based on the phase error.

Abstract: A multiple band direct conversion radio frequency (RF) transceiver integrated circuit (IC) includes a multiple band direct conversion transmitter section, a multiple band direct conversion receiver section, and a local oscillation module. The multiple band direct conversion transmitter section includes a transmit baseband module and a multiple frequency band transmission module. The multiple band direct conversion receiver section includes a multiple frequency band reception module and a receiver baseband module. The local oscillation generation module is coupled to generate a first frequency band local oscillation when the multiple band direct conversion RF transceiver IC is in the first mode and coupled to generate a second frequency band local oscillation when the multiple band direct conversion RF transceiver IC is in the second mode.

Abstract: A variable bandwidth filter for use in filtering signal channels in a telecommunication satellite between uplink and downlink beams, and having a reduced amount of phase noise, includes a first mixer for translating the frequency of an input signal by a first predetermined frequency value, a first filter for defining one edge of the variable bandwidth, a second mixer for translating the frequency of the input signal by a second predetermined frequency value, a second filter for defining another edge of the variable bandwidth, and further mixer for translating the frequency of the input signal by a further predetermined frequency value, and wherein first and second local oscillator frequencies are applied to the first mixer, the second mixer and the further mixer such that each frequency translation of the input signal in one direction has a counterpart translation of corresponding value in the opposite direction.

Abstract: Frequency translation and applications of same are described herein. Such applications include, but are not limited to, frequency down-conversion, frequency up-conversion, enhanced signal reception, unified down-conversion and filtering, and combinations and applications of same.

Abstract: At a transmitting side, during carrier leak adjustment, quadrature modulation means uses a carrier wave having a frequency different from that at a receiving side to quadrature-modulate an outgoing signal. Feedback means feeds a modulated wave resulting from the quadrature modulation back to the receiving side. At the receiving side, quadrature demodulation means quadrature-demodulates the fed back modulated wave. Phase locking means locks the phase of the signal resulting from the quadrature demodulation to match the phase to the phase at the transmitting side. Offset detection means time-averages the phase-locked signal to detect a direct-current offset. At the transmitting side, based on the value of the direct-current offset detected at the receiving side, offset adjustment means corrects a direct-current offset of the outgoing signal to be quadrature-modulated.

Abstract: A method and an apparatus for frequency synthesizing are provided for a wireless communication system. In a frequency synthesizer, a phase lock loop (PLL) circuit generates a first elemental frequency based on a reference frequency and a unity frequency. A first division module then divides the first elemental frequency to generate a second elemental frequency. A second division module divides the second elemental frequency a multiple of times to generate the unity frequency and a plurality of intermediate frequencies each having an exponential ratio to the unity frequency by a power of two. A second mixer is provided to mix one of the intermediate frequencies with the unity frequency to generate a step frequency, and a first mixer mixes the step frequency with one of the first and second elemental frequencies to generate an output frequency having a variety covering all frequency bands in an Ultra-Wide-Band (UWB) spectrum.

Abstract: A wireless communication system of the invention comprises a plurality of communication stations decentralized-autonomously construct a network without having a relation between a control station and a station to be controlled under a communication circumstance where a plurality of channels are prepared. In this case, each of the communication stations prepares a plurality of operation modes for activating transmitting and receiving operations, informs the own operation mode, and receives information regarding operation modes of peripheral stations to manage its operation mode of each of the peripheral stations.

Abstract: Circuits and methods for frequency modulation (FM) using a digital frequency-locked loop (DFLL). A digitally controlled oscillator (DCO) generates and adjusts a frequency of a modulated signal based on a digital tuning word. A DFLL control logic circuit receives a feedback of the modulated signal and generates a carrier signal word. A sigma delta modulator circuit receives an input signal and applies dithering to produce a dithered input signal word. An adder circuit receives and sums the dithered input signal word and the carrier signal word to produce the digital tuning word. The DFLL control logic circuit adjusts the carrier signal word to lock a carrier frequency of the modulated signal.

Abstract: A phase modulation method with a polar transmitter. A target frequency is first designated by comparing the RF signal with a reference frequency and the phase sample. An oscillator control word is generated based on the target frequency. A digital oscillator can modulate from a first phase to a second phase to synthesize a preliminary RF signal based on the oscillator control word. When the target frequency exceeds the modulation capability of the digital oscillator, the oscillator control word is generated based on the target frequency minus 180 degrees, and the preliminary RF signal is shifted by 180 degrees to be the RF signal having the target frequency. When the target frequency does not exceed the modulation capability of the digital oscillator, the oscillator control word is generated solely based on the target frequency to output the preliminary RF signal to be the RF signal having the target frequency.

Abstract: Circuits and methods for modulators that receive symbols, and provide I (incident, or in-phase) and Q (quadrature) component values from a look-up table for subsequent filtering and digital-to-analog conversion. The I and Q component values depend on frequency correction and time index signals such that operating frequency differences between a handset and base station are compensated for, and the transmitted symbols are continuously phase shifted by 3?/8 radians.

Abstract: Aspects of a method and system for a radio data service (RDS) demodulator for a single chip integrated Bluetooth and frequency modulation (FM) transceiver and baseband processor are presented. Aspects of the system may include circuitry on a single chip that enables demodulation of an RDS signal, filtering of the RDS signal, and detection of binary bits in the filtered RDS signal. The filtered RDS signal may be generated by filtering the RDS signal based on a raised cosine filter, or a doublet filter. In general, the RDS signal may also be filtered by a filter that is a first, or greater derivative of a Gaussian filter in either the time or frequency domain. Aspects of the method may include demodulating the RDS signal, filtering the RDS signal, and detecting binary bits in the filtered RDS signal.

Abstract: An FM-band transmit power amplifier and a method of transmitting in multiple bands. In one embodiment, the FM-band transmit power amplifier has an input and an output and includes: (1) a pre-filter including a charge-pump based integrator coupled to the input and a passive notch filter having a notch frequency in a band other than an FM band and (2) an output driver coupled between the passive pre-filter and the output and having PMOS and NMOS transconductors configured to receive an output from the passive filter.

Abstract: An offset history table is implemented and maintained in a BLUETOOTH device and is used to pre-seed an expected frequency offset of a received signal from another BLUETOOTH device. The disclosed offset history table includes one entry for each piconet device in a particular piconet, each entry including a best guess of the relevant piconet device's frequency offset with respect to the receiving BLUETOOTH device. Using a frequency offset history table and a pre-seeded frequency offset corresponding to an expected frequency offset based on the offset value maintained in the frequency offset history table, the performance of a BLUETOOTH device can be increased in a steady state piconet scenario.

Abstract: For transmitting a common channel signal with characteristics with an approximated non-directivity, the common channel signal for all users is divided into sub-channel signals, corresponding to a number of antenna elements composing an array antenna, to be concurrently transmitted with non-directivity by using each antenna element. Individual channel signals, for each user, following the common channel signal with a desired directivity by using the antenna elements. Each sub-channel signal can be made a sub-channel signal obtained by dividing all sub-channel components composing the common channel signal for each sub-channel component by a predetermined number or dividing them depending on a receiving quality of each antenna element.

Abstract: A method and system for generating noise in a frequency synthesizer are provided. The method includes generating a noise portion of an input signal within the frequency synthesizer and appending the noise portion to a control portion of the input signal.

Abstract: A power supply for charging multiple devices that can be adapted to receive and charge practically any type of portable electronic device includes a base that receives an AC wall voltage and converts the wall voltage to DC voltage. The base includes at least two docking cavities that can simultaneously, physically and electrically couple the base to two portable electronic devices such that the devices are supported by the dock while they are being charged. The devices are supported so that there displays are visible and their controls are accessible. Adapters can also be inserted into the docking cavities to reconfigure the cavity to physically support a different type of device.

Abstract: A direct synthesis transmitter. A very efficient and highly linear direct synthesis transmitter is provided that can be used to directly synthesize and transmit any type of modulated signal. The direct synthesis transmitter includes a phase-locked loop (PLL) with controls phase modulation plus an accompanying variable gain amplifier for amplitude modulation. Also included is a system to align the phase and amplitude modulation signals. A transmitter constructed in accordance with the present invention is very efficient and suitable for use in portable radio equipment.

Abstract: An auto frequency control method of this invention has a first step of a base station BS detecting a frequency deviation ?fBS of an uplink signal transmitted from a mobile station MS, a second step of the base station BS transmitting an instructing amount of increase or decrease fcont of the transmission frequency fMS of the uplink signal to the mobile station MS on the basis of the frequency deviation ?fBS of the uplink signal, and a third step of the mobile station MS shifting the transmission frequency fMS of the uplink signal according to the instructing amount of increase or decrease fcont transmitted from the base station BS.

Abstract: Continuous phase frequency shift keying modulation is employed during wireless transmission from an internal device to an external device to increase robustness of transmissions. The continuous phase frequency shift keying processor receives as input an incoming data stream and includes a timer for toggling its output between a first predetermined frequency and a second predetermined frequency on a predetermined time period basis based on the logical state of each bit in the incoming data stream. For a portion of time while the counter or timer of the CPFSK processor is counting down the predetermined time period associated with the detected logic state of a particular bit of the incoming data signal at least some of the other circuitry, preferably all of the other circuitry of the processor, is toggled to a sleep mode in which power is cut off thereby minimizing power consumption by the processor during this interim state.

Abstract: The invention relates to a method and an arrangement for reducing interference in a radio apparatus. The solution comprises a clock signal generator, an analog part and a controller arranged to measure interference arising from the harmonic frequencies of the clock signal on the given radio channel, and a controller for controlling the pulse width of the clock signal on the basis of the measurement.

Abstract: Provided is a transmission circuit capable of operating with high linearity and with low noise. An AM variable fc filter 102 uses an AM cutoff frequency to remove a high frequency component from an amplitude signal. An amplifier 105 supplies a power amplifier 107 with a voltage which is a result of amplifying the amplitude signal outputted from the AM variable fc filter 102. A PM variable fc filter 103 uses a PM cutoff frequency to remove a high frequency component from a phase signal. A phase modulator 104 phase-modulates the phase signal outputted from the PM variable fc filter 103 to output a high-frequency phase-modulated signal. The power amplifier 107 amplifies the high-frequency phase-modulated signal by using the voltage supplied from the amplifier 105, and outputs a resultant signal as a transmission signal.

Abstract: Aspects of a method and system for calibration in an FM transceiver system with off-chip control may include, in an integrated FM system comprising an FM radio transmitter, an FM radio receiver and a common local oscillator, receiving one or more control signals that control calibration of the integrated FM system. Responsive to the one or more control signals, one or more RF carrier signals and corresponding phase-shifted versions of the generated one or more RF carrier signals may be generated via the common local oscillator. The FM radio transmitter and/or the FM radio receiver may be calibrated based on an RF calibration signal generated from the one or more RF carrier signal and/or the corresponding phase-shifted versions of the generated one or more RF carrier signals. An in-phase baseband signal component associated with the generated RF calibration signal may be zeroed.

Abstract: Systems and methods of upstream communications using frequency modulation are disclosed. An exemplary method embodiment, among others, includes frequency modulating a communications signal, intensity modulating the frequency modulated signal, and applying that intensity modulated signal to a transmission medium. Also disclosed is a method of receiving the upstream signal including intensity demodulating the signal received from the transmission medium and frequency demodulating the resultant signal.

Abstract: A method and apparatus are provided to generate calibration signals to multiple stages in a receiver channel. The multiple stages are calibrated using multiple calibration circuits, where a controller controls each calibration circuit. The controller is coupled to the output of the final stage in the receiver channel through a single comparison unit. The output from the single comparison unit is used by the controller to calibrate each of the multiple stages.

Abstract: A data generating unit sets a predetermined value to a data item, which can be made as a reference for tuning at a receiver, so as to generate data of RDS/RBDS format. A frequency modulator modulates the frequency of the data of the RDS/RBDS format generated by the data generating unit, and outputs the frequency-modulated data. The data item may be a program type. The program type is set independently of the type of the data transmitted from the FM transmitter. The receiver tunes with the value of the program type set to the predetermined value.

Abstract: A radio channel simulator configured to read radio channel data describing a radio channel and user data including at least one user signal, and to simulate the radio channel using a FIR filter comprising one or more FIR blocks for filtering the user data read based on radio channel data in connection with the simulation. The radio channel simulator is configured to transfer at least one FIR block at a delay level depicting a radio channel delay during simulation.

Abstract: A transmission circuit capable of transmitting a modulated wave signal using polar modulation in a broad band and with low power consumption is provided. The transmission circuit generates an amplitude signal and a phase signal based on data to be transmitted, and separates the amplitude signal into a low-frequency amplitude signal and a high-frequency amplitude signal. The transmission circuit amplitude-modulates the phase signal in a broad band using the high-frequency amplitude signal in a high-frequency voltage control section 104 and an amplitude modulation section 105 and amplitude-modulates the phase signal into low power consumption using the low-frequency amplitude signal in a low-frequency voltage control section 106 and amplitude modulation section 107.

Abstract: There provides a two-point modulation phase modulation apparatus capable of obtaining an RF phase modulation signal of superior modulation precision with low power consumption and a simple configuration even in the event of inputting a wide band baseband modulation signal. A differentiator (21) of the opposite characteristics to the attenuation characteristics of anti-alias filter (22) is provided at the front stage of a D/A converter (6). As a result, it is possible to sufficiently suppress an alias signal without raising the sampling frequency of the D/A converter (6) (i.e. low power consumption) using an anti-alias filter (22) of a simple configuration (i.e. low cost) with a low order for a narrower bandwidth than a PLL modulation frequency bandwidth, and it is possible to obtain an RF phase modulation signal where the entire frequency band of input digital baseband modulation signal (S1) is reflected in a superior manner.

Abstract: A phase lock loop receives a baseband signal which has an input frequency, and modulating the baseband signal to be a corresponding RF signal which has a predetermined transmission frequency for transmitting. The phase lock loop comprises a programmable divider, a modulator, a phase detector, a charging pump, a loop filter, a voltage-controlled oscillator and a frequency converter. The programmable divider divides the frequency of a local oscillating signal by a programmable divisor to generate a reference signal. The modulator receives the baseband signal, modulates the frequency of the reference signal according to the baseband signal, and generates a corresponding first comparison signal. The frequency converter receives the feedback RF signal and the local oscillating signal and outputs the second comparison signal according to the frequency difference. The divisor of the divider is programmable to avoid the spur frequency being generated because the local oscillating signal is interfered.

Abstract: A method of controlling a phase locked loop in a mobile station and a mobile station of a cellular telecommunications system are provided. The mobile station comprises an integrated phase locked loop for generating output frequencies; a frequency control unit for providing a frequency control word for the phase locked loop, according to which frequency control word an output frequency is generated; and a tuning unit for providing a synchronized tuning word for the phase locked loop, the tuning unit being configured to output the synchronized tuning word to the phase locked loop in synchronization with the output of the frequency control word. The invention reduces the settling time of a mobile station when an operating frequency is changed from one to another.

Abstract: A synchroniser for use in a receiver which receives signals, wherein the synchronizer provides a digital control signal, the control signal defining a plurality of different levels; controls the level provided by successive ones of the control signals, successive ones of the control signal defining different values; and estimates the difference between the levels of successive ones of the control signals.

Abstract: A sample acquisition apparatus for sampling first and second signals within a signal processing arrangement, includes a sampler for capturing sections of the waveforms of both the first and second signals, a switch for alternating correction of the sampler to a point in the arrangement where said first signal can be sampled and a point in said arrangement where said second signal can be sampled. A timer for timing the operation of the switch causes the sampler to capture a first waveform section of the first signal and a second waveform section of the second signal, wherein the second signal is responsive to the first signal and the timing of the switch is such that the second section includes a portion that has been generated in response to the first section.

Abstract: Components of a radio-frequency (RF) apparatus including transceiver circuitry and frequency modification circuitry of a crystal oscillator circuit that generates a reference signal with adjustable frequency may be partitioned in a variety of ways, for example, as one or more separate integrated circuits. The frequency modification circuitry may be implemented as part of a crystal oscillator circuit that includes digitally controlled crystal oscillator (“DCXO”) circuitry and a crystal. The frequency modification circuitry may include at least one variable capacitance device and may be employed to generate a reference signal with adjustable frequency. The adjustable reference signal may be provided to other components of the RF apparatus and/or the RF apparatus may be configured to provide the adjustable reference signal to baseband processor circuitry.

Abstract: The invention relates to a method and device for performing channel simulation, the device comprising a set of channel simulation units (200 to 214) for simulating a radio channel, each unit comprising radio frequency parts (200A to 214A) and baseband parts (200B to 214B). In the solution of the invention, the baseband parts of several different units (200 to 214) are arranged to simulate the same channel.

Abstract: A radio frequency transmitter includes a digital baseband and coding module, an inverse fast Fourier transform (IFFT) module, a complex digital filter, a complex digital-to-analog converter and a radio frequency modulation module. The digital baseband and coding module is operably coupled to convert outbound data into outbound symbols in accordance with a baseband encoding protocol. The IFFT module is operably coupled to convert the outbound symbols into a complex time domain sample sequence. The complex digital filter is operably coupled to filter the complex time domain sequence such that signal strength of outbound RF signals in an exclusion RF band is at or below a specified signal strength with negligible attenuation on in-band signal strength.

Abstract: A data transmission device using electromagnetic wave radiation in a contactless transceiver system toward a contactless object, the data bits transmitted corresponding to the half cycle of an initial time interval during which electromagnetic waves are emitted at a predetermined carrier frequency and to a second splitting time interval during which there is a split in transmission of the electromagnetic waves at the predetermined carrier frequency. During said second splitting time interval, generation means (40, 42, 44, 46, 48) generate electromagnetic waves having a frequency which is double the predetermined carrier frequency resulting in an attenuation of the radiated field by the antenna greater than a predetermined value such as 30 dB.