Abstract: A phase-locked loop (PLL) may include a phase-frequency detector (PFD), a phase interpolation (PI)-based sampler, a loop filter, a voltage-controlled oscillator (VCO), and a fractional frequency divider. The PFD output corresponds to a phase error between a reference clock signal and a feedback signal. The PI-based sampler produces a slope signal in response to the PFD output, and adjusts the slope signal in response to a quantization error correction indication. The PI-based sampler also samples the slope signal. The loop filter produces a VCO control signal in response to a sampled slope signal. The VCO control signal controls the VCO frequency. The fractional frequency divider circuit divides the frequency of the VCO output signal and also determines the quantization error correction corresponding to the quantization error introduced by fractional division of the frequency of the VCO output signal.

Abstract: An emphasis signal generating circuit includes: a branch and delay unit configured to branch an input signal, delay a branched signal, and output a first delayed signal; a high-frequency extraction unit configured to extract at least one of high-frequency components of the input signal and the first delayed signal to output a high-frequency signal; and an addition and subtraction unit configured to add and subtract the input signal, the first delayed signal, and the high-frequency signal.

Abstract: Various embodiments are directed to systems and methods for combining a plurality of codes. The plurality of codes may be binary codes having possible logical values of ?1 and +1 and may comprise an even number of codes. An output of the combining v0,k may be given by: v0=sgn(vi), where vi is the sum of the first plurality of codes at the first time. Embodiments for allocating different power levels among various codes are presented.

Abstract: A pre-distortion circuit that may introduce a pre-distortion signal in a communication channel by determining a harmonic signal of the signal to be output. One or more image correction signals of the signal to be output may be determined. The one or more image correction signals may be complex conjugate signal variations of the signal to be output. The harmonic signal, the one or more image correction signals and the signal to be output may be combined into a combined output signal. The combined output signal may be transmitted to a digital-to-analog converter. The predistortion circuit may be implemented in a FPGA, an ASIC, a digital-to-analog converter, and/or a separate IC package.

Abstract: In an emphasis optimization device, a calculating unit calculates an inverse characteristic of an amplitude characteristic based on the amplitude characteristic of a transmission path, and an inverse Fourier transform unit performs an inverse Fourier transform on the inverse characteristic to obtain an impulse response. An extracting unit extracts, from the obtained impulse response, an impulse response corresponding to the number of taps necessary for emphasis to be added to a digital signal to be transmitted on the transmission path. An emphasis amount calculating unit converts the extracted impulse response into a value of the emphasis to calculate an emphasis amount.

Abstract: A peak suppressing apparatus includes a pre-emphasis section that performs a pre-emphasis process on a signal, which is to be wirelessly transmitted and a peak of which is to be suppressed, the pre-emphasis process emphasizing a given frequency range component of the signal, a clipping section that limits, to a given threshold value, an amplitude of the signal that has been subjected to the pre-emphasis process, a de-emphasis section that performs a de-emphasis process on the signal, whose amplitude has been limited, the de-emphasis process suppressing the given frequency range component of the signal, and a frequency converter that converts, to allow wireless transmission, a frequency of the signal that has been subjected to the de-emphasis process.

Abstract: An application for a two-way communication system for communicating with a person who is within a second vehicle includes a short-range radio transmitter within a first vehicle to transmit audio to a radio within the second vehicle. Communication from the person in the second vehicle to a person in the first vehicle is performed by aiming a light beam from the first vehicle at the second vehicle and receiving reflections of the light beam at the first vehicle. The light beam is modulated by vibration of the second vehicle caused by the person speaking in the second vehicle. The received light beam is then processed to reproduce the sound of the person's voice.

Abstract: A phase locked loop device includes a phase detector that measures a difference in phase between a reference clock signal and an output clock signal provided to a device module. The phase detector provides a pulse having a width indicative of the phase difference. If the phase difference exceeds one of a plurality of threshold values, an indicator can be asserted. Based on the indicator, a control module can take remedial action, such as providing a different clock signal to the device module or triggering an interrupt at a processor device.

Abstract: An application for a two-way communication system for communicating with a person who is within a vehicle includes a short-range radio transmission to transmit audio to a radio within the vehicle. Communication from the person is done by reflecting a light beam on a window of the vehicle and receiving the light beam. The light beam is modulated by vibration of the window caused by the person's voice. The received light beam is then processed to reproduce the sound of the person's voice.

Abstract: Apparatus and methods apply pre-emphasis to the phase rather of a signal than to the amplitude of a single. This approach can provide superior pre-emphasis performance than the conventional amplitude pre-emphasis techniques in certain situations, such as when a non-linear slicer is present in the signal path. For example, electrical-to-optical (E/O) and optical-to-electrical (O/E) converters can effectively slice a signal.

Abstract: In one embodiment, a method of wirelessly transmitting magnetic resonance (MR) data is provided. The method comprises steps of obtaining at least one MR signal having a Larmor frequency from a radio frequency (RF) channel in an RF coil, the RF coil comprising multiple RF channels, each RF channel associated with a single imaging element, generating a modulation signal based on the MR signal, generating a carrier signal with a predetermined frequency, the predetermined frequency being associated with the RF channel and using the modulation signal to phase modulate the carrier signal to form a phase-modulated signal.

Abstract: An application for a two-way communication system for communicating with a person who is within a closed vehicle includes a short-range radio transmission to transmit audio to a radio within the vehicle. Communication from the person is done by reflecting a light beam on a window of the vehicle and receiving the light beam, which is modulated by vibration of the window caused by the person's voice. The received light beam is then processed to reproduce the sound of the person's voice.

Abstract: A method of fighting interference in a frequency-hopping communication system is disclosed. The system has at least one main sensor and one or more auxiliary sensors. According to at least one embodiment, frequency-hopping signals are received. The frequency-hopping signals are arranged to include useful bands and one or more guard bands inserted between the useful bands, and a ratio of the useful bands to the guard bands being chosen according to a predetermined value of probability of interference interception. Signals of the inserted guard bands having a signal level greater than a predetermined threshold are selected. A set of spatial-filtering weightings are calculated according to a correlation matrix of noise plus jammers alone on the signals selected. Baseband signals of the received frequency-hopping signals are filtered by the set of the calculated spatial-filtering weightings.

Abstract: A method for clipping a baseband input signal filters the complex baseband input signal with a function H1 for forming a filtered first signal. To form a clipped signal in the baseband the filtered first signal is multiplied by a scaling factor. By a signal analysis of the filtered first signal signal overshoots are predicted from which the scaling factor is determined for the baseband clipping. The filter function H1 is calculated as the quotient from a frequency response HS of a transmission filter used one the one hand and from an error frequency response HF on the other hand, with the error frequency response HF being determined in such a way that the error spectrally shaped with HF, which arises for the limitation of the baseband signal, a frequency-dependent tolerance is not exceeded. Subsequently the clipped signal is filtered with the error frequency response HF for forming a filtered second signal.

Abstract: A Generalized Rake (G-Rake) receiver is adapted for Golden code reception in a CDMA system. Signals transmitted by two or more transmit antennas are received at two or more receiver antennas. The signal from each receiver antenna is despread, and channel estimation is performed for each transmit antenna. G-Rake combining weights are calculated based on impairment correlation across G-Rake fingers and channel coefficients corresponding to each transmit antenna. The despread values from each symbol period are combined over a plurality of symbol periods based on the combining weights. The combined values are processed using coefficients derived from the Golden number to generate a set of decision variables, and the Golden encoded symbols are jointly detected from the decision variables. In some embodiments, spherical decoding and triangularization significantly simplify the decoding problem formulation.

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: Delay estimation apparatus and method, comprising: a correlation step which a correlation function between a received signal and a supplied template waveform is generated, AD conversion step at which said correlation output generated at said correlation step is uniformly sampled into discrete samples; and arithmetic operation step at which a time delay estimate of the received signal based on said discrete samples generated at said AD conversion step is computed, wherein a selection criterion depending on the digital sampling frequency used at said AD conversion means is checked, if said selection criterion is satisfied, computes the time delay estimate based on the direct pick method, and if said selection criterion does not hold, computes the time delay estimate based on the simplified maximum likelihood (ML) method.

Abstract: A communication system includes a storage device having a storage area accessed in one of a page unit and a sector unit; a control device operable to request access to data in a file unit; and a predetermined transmission line for transmitting data between the storage device and the control device. The control device transmits to the storage device via the transmission line a request for access to one of each page and each sector forming a file for which access has been requested, and the storage device sequentially accesses one of a requested page and a requested sector, whereby a request for access to the entire file is realized in the storage area.

Abstract: One or more embodiments of the invention comprise a continuous-time equalizer (CTE) for reducing both pre-cursor and post-cursor intersymbol interference (ISI) from data received from a communication channel. One such equalizer comprises two independent stages that process the input signal in parallel. One stage subtracts a scaled version of the derivative of the input signal from a scaled version of the input signal to reduce pre-cursor ISI from the input signal. The other stage adds a scaled version of the derivative of the input signal to a scaled version of the input signal to reduce post-cursor ISI from the input signal. The outputs from the two stages are then multiplied to arrive at an output signal in which both pre- and post-cursor ISI is minimized. Because the scalars used in each of the stages are independent, each can be adjusted for greater manipulation of the ISI-reduced signal.

Abstract: Various embodiments are disclosed relating to sound enhancement for wireless audio devices. A technique may include determining one or more user-specific audio processing parameters, receiving an RF signal from a first wireless device, demodulating the received RF signal to obtain an audio signal, processing the audio signal based on the one or more user-specific audio processing parameters to generate a user-specific audio signal. The user-specific audio processing parameters may be based on user preferences, or may, for example be based on a user auditory profile or other information to allow a received audio signal to be processed to at least partially compensate for a user's specific hearing impairment.

Abstract: An embodiment of the present invention provides transmitter having a phase locked loop that has a dynamically controllable loop bandwidth. A transmit modulator is coupled to the PLL for performing vector modulation in response to transmission symbols. Each transmission symbol comprises an amplitude signal and a phase signal. A controller is coupled to the PLL and to the transmit modulator and is operable to detect when a criteria of the transmission symbols crosses a threshold and to adjust loop bandwidth in response to crossing the threshold. The criteria of the transmission symbols may be a function of the amplitude signal or a function of the phase signal, and may be the amplitude signal, a first derivative of the amplitude signal, a second derivative of the amplitude signal, a square of the amplitude signal, a derivative of the amplitude signal squared, the phase signal, or a derivative of the phase signal.

Abstract: A receiver architecture for receiving an FSK signal having a predetermined number of modulation levels includes a selectivity filter (206) for selectively passing a wanted channel and rejecting unwanted channels. The selectivity filter has a filter bandwidth of about one-half the bandwidth of a pre-modulation filter in a transmitter sending the FSK signal. A discriminator (208) is coupled to the selectivity filter for demodulating the signal. A symbol recovery processor (210) is coupled to the discriminator for recovering the symbols through a maximum likelihood sequence estimation (MLSE) technique utilizing N states for each symbol time, wherein N equals the predetermined number of modulation levels, and wherein templates used in the MLSE for symbol transitions are optimized with a bandwidth substantially less than the bandwidth of the pre-modulation filter.

Abstract: Disclosed is a code tracking apparatus and method under a multi-path environment in a DS-CDMA communication system.

Abstract: A pre-emphasis circuit and methods are provided. The circuit includes a first amplifier and a second amplifier. The first amplifier contains M first driver cells and is operable to amplify a signal. The second amplifier contains P second driver cells and is operable to amplify a delayed version of the signal The pre-emphasis circuit further includes logic circuit operable to change a pre-emphasis ratio of the pre-emphasis circuit including switching off one or more of the M first driver cells of the first amplifier and switching on a corresponding one or more of the P second driver cells of the second amplifier, such that a swing amplitude for an output signal provided by the pre-emphasis circuit is maintained at a constant level.

Abstract: The present invention relates to a high speed line equalizer and a method thereof. The high speed line equalizer receives and amplifies one clock signal and at least more than one data signal. The high speed line equalizer comprises an input buffer, a first filter, at least more than one second filter, and an adaptive loop. The input buffer amplifies the clock signal. The first filter controls a high frequency gain of the clock signal according to a gain control signal. The at least more one second filter controls a high frequency gain of the at least more than one data signal according to the gain control signal. The adaptive loop calculates a gain difference between high frequency components of the amplified clock signal from the input buffer and the clock signal of which high frequency gain is controlled and outputs the gain difference as the gain control signal.

Abstract: The present invention provides a FM transmitter with Radio Data System (RDS) data transmission capability. In one embodiment, an RDS circuit is implemented in firmware. The firmware is configured in one or more stages to allow the RDS system to be integrated with a variety of FM transmission systems.

Abstract: A method encodes a sequence of blocks of input bits to be transmitted over a wireless channel. Each block of input bits is converted to a codeword, and each codeword is mapped to multiple sub-blocks of complex numbers. Each sub-block is multiplied by a disambiguating spreading transform to obtain a sub-block of transformed symbols, which can be modulated and transmitted to a receiver, where each received block is demodulated to a block of complex numbers, which are partitioned into sub-blocks. The sub-block of complex numbers are converted to a set of likelihood ratios that correspond to decoded codewords. The input bits can be decoded unambiguously even if only one of the blocks of symbols corresponding to the block of input bits is received correctly.

Abstract: Disclosed herein is a 2N-order sub-harmonic frequency modulator and direct conversion transmitter using the same. The direct conversion transmitter includes a digital modulation unit, a D/A conversion unit, a DC correction and low pass filter unit, a local oscillator, a poly phase signal generation unit, a 2N-order sub-harmonic I/Q frequency modulation unit, a power amplification unit, and an antenna. The digital modulation unit digitally modulates a base-band signal and then outputs I and Q component signals. The D/A conversion unit converts the I and Q component signals into analog I and Q component signals. The DC correction and low pass filter unit adjusts DC interfaces of the analog I and Q component signals, passes low frequency components of the analog I and Q component signals and generates I and Q components of a base-band signal. The local oscillator generates a sine wave signal with a frequency of FTX/2N. The poly phase signal generation unit generates a poly phase signal with 2N+1 phases.

Abstract: A cellular telephone is used as a remote control device to control operations on the users nonportable computer which is remote location to the cellular telephone. The user can carry out various operations on the cellular telephone which cause the remote computer to take some additional action.

Abstract: Disclosed are a forward multiple scrambling code generating method and apparatus in a communication system. Each base station uses primary scrambling codes and an associated one of secondary scrambling code sets, each consisting of a plurality of secondary scrambling codes. When an n-th one of the primary scrambling codes is to be generated, an initial value of the scrambling code generator is set with a binary value of “n,” so that a desired primary scrambling code is generated using the initial value. When an n-th one of the secondary scrambling codes in an m-th one of the secondary scrambling code sets is to be generated, an initial value of the scrambling code generator is set with a value obtained by shifting the n-th primary scrambling code by m times, thereby generating a desired secondary scrambling code.

Abstract: A digital control device for tracking a sine wave according to the present invention has a compensator, a control object and a feedback gain. An input into the compensator is a signal obtained by subtracting a control quantity from a reference value. An input into the control object is a signal obtained by subtracting an output of the feedback gain from an output of the compensator. A transfer function of the compensator is (k2z+k1)/(z2?2z cos ?T+1), where ? is an angular frequency, T is a sampling period, z is a z operator, and k1 and k2 are constants. Thus, a second-order compensator can be configured, with which a sinusoidal reference waveform can be tracked simply and with high accuracy.

Abstract: Various methods and systems disclosed compand audio signals using signal prediction, followed by expansion and reconstruction. The methods and systems compress and expand an error signal that represents deviations between samples of the original signal and predicted samples. Each predicted sample is generated by an extrapolation based on a sub-sequence of prior samples of the original signal. A time series of correction samples based on the error signal as it is received from the analog channel after amplitude expansion. Output samples are then generated from the sums of the correction samples and respective predicted samples of a second time series, each of which is extrapolated based on a sub-sequence of prior correction samples. Numerous variations are also disclosed.

Abstract: In some embodiments, a transmitter includes first encoding controlled frequency output circuitry to creates a magnitude encoded controlled frequency signal (CFS) and second encoding controlled frequency output circuitry to create a complementary a magnitude encoded controlled frequency signal (CCFS). Other embodiments are described and claimed.

Abstract: A high-speed bit stream interface module interfaces a high-speed communication media to a communication Application Specific Integrated Circuit (ASIC) via a Printed Circuit Board (PCB). The high-speed bit stream interface includes a line side interface, a board side interface, and a signal conditioning circuit. The signal conditioning circuit services each of an RX path and a TX path and includes a clock and data recovery circuit and an output pre-emphasis circuit. The output pre-emphasis circuit controllably modifies the spectrum of the high-speed bit stream to pre-compensate for the spectral characteristics of a signal path upon which the high-speed bit stream will be output. In the RX path, pre-compensation is performed based upon the properties of the PCB and a servicing connector. In the TX path, pre-compensation is performed based upon the properties of a line side connector and a line side media.

Abstract: A pre-emphasis circuit and methods are provided. The circuit includes a first amplifier and a second amplifier. The first amplifier is operable to amplify a signal using a first amplifier current, and the second amplifier is operable to amplify a delayed version of the signal using a second amplifier current. The pre-emphasis circuit further includes a logic circuit operable to change a pre-emphasis ratio of the pre-emphasis circuit including switching off one or more of first driver cells of the first amplifier and switching on a corresponding one or more of second driver cells of the second amplifier, such that a total current consumption of the first amplifier and the second amplifier remains substantially constant.

Abstract: The invention relates to a new design of discharge vessel for a discharge lamp, in which dielectrically impeded discharges are to be generated. In this case, a discharge vessel plate 1, 9 is, as it were, of two-fold design, specifically as a first discharge vessel plate 1 with an external electrode set and, in addition, as a stabilizing plate 9 outside the first discharge vessel plate 1.

Abstract: A method and apparatus for generating a burst FSK signal having precisely shaped transitions between modulation states. The apparatus uses feedforward compensation of phase gain and phase preemphasis coefficients for compensating the frequency conversion gain of the apparatus, and the phase gain coefficient is used for stabilizing a frequency synthesis loop. The phase gain and preemphasis coefficients are determined in a calibration within the time constraints of on-line signal bursts based upon measured phase errors and accelerated predicted phase gain and preemphasis phase errors.

Abstract: An improvement for a phasor fragmentation engine and method, whereby a phasor flipping algorithm is applied when determining fragment phasors for a non-constant envelope modulation signal (e.g. OFDM). The phasor flipping algorithm avoids sharp phase transitions for the fragment phasors, which cause an increase in bandwidth, by performing a comparison of the phasor angle separation between the prior and current time samples. This comparison corresponds to a determination of whether the modulation signal V has passed near or through zero.

Abstract: Bandwidth reduction of amplitude and/or phase components of relatively wide bandwidth composite signal. In an exemplary embodiment, an EER amplifier system for CDMA signal amplification includes an amplitude bandwidth reduction module included in an amplitude signal component path and a phase bandwidth reduction module is included in a phase signal component path, for controlling an RF amplifier. The phase bandwidth reduction module may reduce the phase component bandwidth of the input signal by, for example, generating a non-linear relationship between phase signal amplitude and input signal amplitude. The amplitude bandwidth reduction module may reduce the amplitude component bandwidth of the input signal by, for example, generating a non-linear relationship between the supply voltage to the RF amplifier and an input signal amplitude.

Abstract: A transmission circuit includes a baseband circuit, spreading section, multiplier, digital modulator, quadrature modulator, and antenna. The baseband circuit generates and outputs at least one transmission data constituted by first and second channel data. The spreading section spreads the transmission data with a spreading code that differs for each transmission channel. The multiplier respectively weights the amplitudes of the first and second channel data by using a combination of two gain factors determined by a transmission data rate. The digital modulator digitally modulates the first and second channel data whose amplitudes are weighted by the multiplier. The quadrature modulator quadrature-modulates the digitally modulated first and second channel data and outputs the data as a transmission signal. The antenna emits the transmission signal output from the quadrature modulator as a radio wave.

Abstract: The present invention relates to a system and method for signaling among a plurality of devices via a communication carrier over a noisy medium such as a power line and particularly relates to an innovative method and system for high speed signaling using an innovative modulating scheme. The scheme is particularly well adapted for signaling over multiple channels and over direct current (DC) power lines. At the transmitter end, a modem modulates data to be transmitted according to a modulation scheme and a signaling shifter modifies the carrier according to a modification scheme. At the receiver end, a modem demodulates the data according to the modulation scheme and a detector detects the signal in accordance with the modification scheme. Signals may be received over multiple channels. A signal is sent over a subset of the channels. Remaining channels can be used for competing signals avoiding interference. The channel chosen for sending a signal may also indicate signal priority.

Abstract: The wireless transmission-reception system of the subject invention includes a transmitter and a receiver. The transmitter includes a compressor for compressing a signal to be transmitted and a pre-emphasis circuit for emphasizing an output signal of the compressor. The receiver includes a demodulator, an expander circuit for expanding an output signal of the demodulator, a first de-emphasis circuit connected to the demodulator in parallel with the expander for de-emphasizing the output signal of the demodulator, and a second de-emphasis circuit connected to an output signal of the expander circuit for de-emphasizing a signal expanded by the expander circuit. The expander circuit having a variable gain amplifier includes a rectifier. An output signal from the first de-emphasis circuit is sent to the rectifier and an output signal of the rectifier performs to control a gain of the variable gain amplifier.

Abstract: A transfer connection device for wirelessly connecting mobile phone and hand-free handset has a first connector and a second connector to respectively couple with a hand-free handset and a mobile phone to allow signal transmission between the hand-free handset and mobile phone accomplished in a wireless fashion without the tangle and inconvenience of physical linking line between the mobile phone and the hand-free handset.

Abstract: The invention relates to a method for supplying reference data that is to be used in a mobile station of a radio communications network for a frequency update of the frequency used by the mobile station, which reference data is based on bursts received by the mobile station from a base station of said radio communications system. In order to allow for an improved supply of reference data to an automatic frequency correction algorithm, it is proposed that the method comprises determining the signal-to-noise-ratio of all bursts received unless they were discarded by some selection process; and providing at least some of the bursts for which a signal-to-noise-ratio greater than a predetermined value was determined as basis for the reference data to be used for the frequency update. The invention equally relates to a mobile station, a module and a radio communications system comprising the corresponding means.

Abstract: A device for a set of radio communication equipment to reduce electromagnetic energy absorbency of a human body, it suits especially the equipment of a mobile phone, a Blue Tooth or a PDA etc. The standing wave ratio at a point 1 is set to be higher than that at a point 2 of the first working frequency of a multi-frequency wave band, so that the SAR value can be largely lowered. In a preferred embodiment, a point 1 of the first working frequency has 880 MHz, while a point 2 has 960 MHz.

Abstract: A communications system includes a transmission system and a receiver system for enabling telecommunication of a voice signal on an appropriate carrier wave across a medium at a low bit-rate and consequently, with high reliability.

Abstract: A nonlinear compensator comprising a signal processing section, a distortion detecting section, and a distortion correcting section. The signal processing section detects the time difference and phase difference between two signals by calculating correlation, synchronizes the two signals with each other, and causes the phase of one signal to coincide with that of the other. The distortion detecting section determines an amplitude error and a phase error in the two signals and inputs the errors as distortion components to a distortion correcting section. The distortion correcting section sequentially selects the amplitude, the phase, and the amount of compensation corresponding to the value of the amplitude from the amounts of compensation registered at the initial stage and updated adaptively, and adds the amount of compensation to the digital base band signal obtained at the input demodulation section to compensate for the distortion components.

Abstract: A method and modem for communicating serial input data over a transmission link are disclosed. Serial input data is partitioned into parallel data elements prior to rotation by an invertible linear mapping. Computationally efficient multi-rate wavelet filter banks are employed in a receiver for analyzing a received signal. Self-interference components are calculated in the receiver per sub-band and tap-weights for the filter banks are derived as a function over the range of self-interference values. A weighted sum is formed and subtracted from the delayed, received signal to eliminate the interference, and is removed from the recovered signal.

Abstract: In transmitting the analog video signal via a coaxial cable, a transmission apparatus side is not provided with an emphasis characteristic which is the inverse to the frequency attenuation characteristic of the coaxial cable. In stead, an emphasis is applied by a preemphasis circuit on the transmission side, on the basis of an emphasis curve of a frequency band characteristic curve having an inverse characteristic to a frequency band characteristic curve of a detected signal which is obtained when transmitting a modulated signal without a preemphasis to the coaxial cable and conducting synchronous detection on a receiving apparatus side by using an oscillation frequency having the same frequency as that of a carrier used at the time of modulation.

Abstract: A subharmonic carrier-canceling baseband/K upconverter system uses a first splitter to separate an incoming RF signal into two equal components: in-phase (1) and quadrature (Q, 180 degrees delayed). A second splitter is used to separate a local oscillator signal into two equal components: in-phase (I) and quadrature (Q, 90 degrees delayed). A first subharmonic mixer is used to mix both I components, while a second subharmonic mixer is used to mix both Q components. The outputs of both mixers are then combined to produce an output RF signal having reduced second order harmonics close to said local oscillator frequency.