Abstract: A signal receiver inputs a signal, computes a set of equalizer tap values during a signal acquisition phase by applying an algorithm iteratively to a given set of training data contained within the signal, and uses the set of equalizer tap values to process the signal during the signal acquisition phase.

Abstract: VSB reception system with a frequency domain equalizer including a demodulating part for receiving, converting, and demodulating a signal, a frequency domain equalizing part for equalizing the demodulated signal for removing a distorted component from the demodulated signal, and a noise removing part for (a) receiving the equalized signal, (b) calculating a reference error signal that is a difference between the equalized signal and the signal having the noise removed therefrom, (c) calculating an error signal that is a difference between the reference error signal and the extracted noise signal, (d) renewing parameters with reference to the reference error signal and the error signal, and (e) calculating a difference between the equalized signal and the extracted noise signal, to provide a signal having the noise removed therefrom.

Abstract: The invention relates to a phase error detector which generates a phase correction signal in such a manner that the phase characteristic curve thereof does not have any undesired zero positions and comprises a finite steepness in the angular area around the engaging point. The inventive phase error detector (PFD) calculates the phase correction signal (S) according to the detected decision domain in accordance with a number of predetermined calculating methods. The phase error detector (PFD) attains such an allocation between the decision domains of the complex QAM single state plane and the individual calculating methods such that the static phase characteristic curve thereof does not have any additional zero positions apart from the engaging point.

Abstract: Processing a received optical signal in an optical communication network includes equalizing a received optical signal to provide an equalized signal, demodulating the equalized signal according to an m-ary modulation format to provide a demodulated signal, decoding the demodulated signal according to an inner code to provide an inner-decoded signal, and decoding the inner-decoded signal according to an outer code. Other aspects include other features such as equalizing an optical channel including storing channel characteristics for the optical channel associated with a client, loading the stored channel characteristics during a waiting period between bursts on the channel, and equalizing a received burst from the client using the loaded channel characteristics.

Abstract: The invention relates to a method of phase controlling a data signal transmitted from a data source to a data sink using a counter clock approach, wherein the phase of a data sink clock is compared with the phase of a reference signal at the data sink and the phase of a counter clock is adjusted at the data sink in dependency to said phase comparing. It relates also to a counter clock circuit arrangement and interface device for performing the method according to the invention.

Abstract: An adaptive equalizer updates its tap coefficients with the aid of an error signal e(k)=sign[z(k)]*(RS?|z(k)|2) where sign[ ] is the sign function, z(k) is the equalizer output at symbol time k, | | is the magnitude function and RS is a positive real constant, which is optimally defined as RS=E{|an|3}/E{|an|}, where E{ } is the mathematical expectation function and an is the information symbol at symbol time n. A generalized equalizer error signal satisfies e(k)=sign[z(k)]*(RSp?|z(k)|p) where RSp is a positive real constant, which is optimally defined as RSp=E{|an|p+1}/E {|an|} and p is a positive integer. The equalizer conducts blind equalization of an Advanced Television Systems Committee-High Definition Television signal and any other one-dimensional modulation system.

Abstract: A method and an apparatus for serial data communication employs a data transmission process which transmits data from one control unit to the another control unit and at the same time checks a reception confirmation signal on each number of the data by transmitting a clock signal, and a data reception process which receives the data on the one control unit from the other control unit and checks a transmission confirmation signal on the each number of the data by transmitting the clock signal. The apparatus comprises a first and a second control unit, four serial buses for performing serial data communication between the both control units, two pull-up operation units for continuing control voltage of the serial buses at a certain level, and a control voltage matching unit for continuing voltage equilibrium condition.

Abstract: A time division duplex (TDD) single sideband (SSB) transceiver includes a transmitter adapted to input an analog audio signal, sample the analog audio signal, and to output an SSB frequency shift keyed (FSK) signal corresponding to the analog audio signal, the SSB FSK signal including analog information. A receiver is adapted to switch between receiving one of an upper sideband and a lower sideband of an external SSB signal.

Abstract: A chopper-direct-conversion (CDC) radio receiver includes a phase-alternating mixer receiving an antenna input signal and at least one local oscillator signal and generating a double sideband signal in a single mixing step. The phase-alternating mixer may be implemented by two parallel mixers each mixing the input signal with one of two local oscillator signals and an adder receiving and summing outputs from the two parallel mixers, by a track-and-hold circuit sampling the input signal based upon the local oscillator signal, or by a window averaging circuit averaging the input signal across a period of the local oscillator signal. The CDC architecture is suitable for fabrication on a single chip and offers solutions to virtually all problems found in conventional direct-conversion receivers.

Abstract: A system and method for processing received transmission signal(s) adapted to be used in high rate communication systems without impairing the received signal energy and without additional expensive components. The system and method are adapted to transmission system(s) having at the receiver-side a compound system of a feed-forward equalizer (FFE) and a subsequent decision feedback equalizer (DFE). A feed forward equalization and/or a decision feedback equalization is performed on the received high rate signal by deriving adaptation information from the equalized signal after a signal decision is performed for adjusting all intended feed forward equalization and/or decision feedback equalization coefficients and/or table entries in dependence on said information.

Abstract: A carrier recovery apparatus includes a first LPF calculating a carrier changing in accordance with a frequency offset, by using a pilot tone included in an I-signal of a VSB broadcasting signal, a limiter limiting a size of the carrier calculated by the first LPF and outputting the limited size of the carrier, a multiplier multiplying the limited size of the carrier from the limiter by a Q-signal of the VSB broadcasting signal, a second LPF extracting a DC-property corresponding to a frequency error of the carrier from a product output from the multiplier, a numerically controlled oscillator (NCO) generating a complex carrier corresponding to the DC-property from the second LPF, and a frequency error providing unit arranged between the second LPF and the NCO, storing the DC-property from the second LPF, and when the pilot tone is distorted by a damaged pilot in the I-signal, providing the NCO with the DC-property that is previously input and stored therein.

Abstract: Device and method for tracking a phase error in a digital TV receiver, wherein a phase noise compensated I signal is subtracted from I level reference signals of VSB signal, to obtain an error of the I signal, a sign of the Q signal having a phase noise thereof compensated is multiplied to the error of the I signal from the error determining part, to estimate a basic phase error, and a phase error compensating area is determined, a preset constant ‘?’ is multiplied to the basic phase error to provide a final phase error in the determined phase error compensating area, and the basic phase error is provided as it is as the final phase error in other areas, thereby estimating the phase error more accurately.

Abstract: A method of processing an AM radio signal comprises the step of receiving an AM radio signal including an upper sideband portion and a lower sideband portion, demodulating the upper sideband portion and the lower sideband portion to produce a demodulated upper sideband signal and a demodulated lower sideband signal, weighting the demodulated upper sideband signal and the demodulated lower sideband signal in response to noise power to produce a weighted demodulated upper sideband signal and a weighted demodulated lower sideband signal, and combining the weighted demodulated upper sideband signal and the weighted demodulated lower sideband signal to produce an output signal. Demodulators which process AM radio signals in accordance with the method, and receivers incorporating the demodulators, are also included.

Abstract: The convergence time of a blind, adaptive equalizer is shortened by using a tracking generator. The tracking generator comprises a smoothing filter which receives and smoothes a tap coefficient error estimate derived from an output data stream. Thereafter, a fraction of the smoothed estimate is generated. It is the use of this function of the smoothes estimate which allows the convergence time to be shortened.

Abstract: A vestigial sideband VSB receiver includes a digital processing part for selecting a desired channel frequency via an antenna and converting the desired channel frequency to an intermediate frequency to digitize a predetermined band of the intermediate frequency, a carrier wave restoring part for extracting pilot components from a signal of the digitized pass band to restore carrier waves, and a demodulator for separating components I and Q from the signal of the digitized pass band and multiplying the components with a complex carrier wave, which is restored in the carrier wave restoring part. The carrier waves are restored by extracting the pilot signals from the pass band and detecting the symmetrical errors of the carrier wave frequency, so that the carrier wave may be stably obtained and pursued with relation to the both positive and negative frequency offsets.

Abstract: A vestigial sideband (VSB) modulation minimum output energy (MOE) pre-equalizer operating on a received ATSC 8-VSB DTV signal includes one or more of an adaptive feed-forward filter and an adaptive feedback filter each utilizing only real adaptive coefficients, with the direct term for the overall filter constrained to unity to remove one degree of filter parameterization freedom. Adaptation of the filter(s) is based on minimizing a blind energy cost function, and is independent of adaptation of a conventional adaptive channel equalizer. The pre-equalized signal is passed to the conventional adaptive equalizer for channel equalization utilizing DFE, IIR-CMA, etc., resulting in performance improvements including faster convergence and greater robustness with relatively small implementation costs.

Abstract: Improved carrier recovery and symbol timing systems and methods suitable for use in connection with a dual-mode QAM/VSB receiver system is disclosed. Carrier and symbol timing acquisition and tracking loops are phase/frequency locked to an inserted pilot signal provided in an input VSB spectrum at a given frequency. An input spectrum is centered about baseband and the pilot is extracted by an equivalent filter which functions as a bandpass filter having pass bands centered about the pilot frequency. Since the pilot signal's frequency is given, its position in the frequency domain for any sampling frequency, is deterministic. The receiver's sampling frequency is provided such that the relationship is expressed as fc=fS/4. When tracked by a phase-lock loop, the pilot signal will appear at the correct location in the spectrum if the sampling frequency fS is correct, and will be shifted in one direction or the other if the sampling frequency fS is too high or too low.

Abstract: In an AM system directed to commercial broadcasting, a pure unmodulated (CW) carrier signal and two sideband signals are generated and processed separately as three independent signals that are summed as output of a final linear mixer. The sideband signals are derived independently utilizing audio spectrum-sharing based on complementary comb filtering, quadrature phase-shifting at both audio and carrier sideband frequencies, and exclusive alternate toggling at a designated switching rate between the two sidebands so that at any instant in time only one of the two sidebands is present along with the continuous carrier. The overall performance provides the capability of advantageous modulation beyond the conventional 100% modulation limit.

Abstract: For a digital demodulator for AM demodulation of a difference sound signal in a digital multiplex signal, which multiplex signal also comprises a sum sound signal in the baseband position and a pilot carrier at a pilot frequency, and the difference sound signal is modulated on a carrier at twice the pilot frequency, an extremely simple and adjustment-free construction is ensured in that CORDICs (1, 7) are provided which perform a coordinate transformation of polar coordinates into cartesian coordinates and each have a phase input, two amplitude inputs assigned to the coordinates x and y and two outputs assigned to the coordinates x and y, in that a phase-locked loop comprising a first CORDIC (1), a loop filter (2) and an accumulator (4) are provided, which phase-locked loop supplies a phase ramp signal whose repetition frequency is dependent on the input signal of the accumulator, in that the multiplex signal at an amplitude input of the first CORDIC (1), the output signal of the accumulator (4) at the phase

Abstract: An apparatus for determining an error ratio of individual channels of a WDM optical signal comprises a wavelength-selective filter for separating the individual channels of the WDM signal and a measurement circuit for measuring an error ratio of one channel using a first decision threshold level. The measurement circuit is operable to cycle through all channels, taking an error ratio measurement for each channel in sequence with a predetermined decision threshold level. Control circuitry alters the decision threshold level for successive cycles of the measurement circuit. The apparatus measures error ratio values for each channel in turn, building up an error ratio vs. threshold pattern enabling the Q value to be obtained. Although the time taken to build up the error ratio pattern for an individual channel is not shortened, measurements are taken on each channel at much shorter intervals.

Abstract: A radio frequency (RF) integrated circuit (IC) includes a local oscillation module, analog radio receiver, analog radio transmitter, digital receiver module, digital transmitter module, and digital optimization module. The local oscillation module is operably coupled to produce at least one local oscillation. The analog radio receiver is operably coupled to directly convert inbound RF signals into inbound low intermediate frequency signals based on the local oscillation. The digital receiver module is operably coupled to process the inbound low IF signals in accordance with one of a plurality of radio transceiving standards to produce inbound data. The digital transmitter is operably coupled to produce an outbound low intermediate frequency signal by processing outbound data in accordance with the one of the plurality of radio transceiving standards. The analog radio transmitter is operably coupled to directly convert the outbound low IF signals into outbound RF signals based on the local oscillation.

Abstract: An integrated multimode radio includes a multimode receiver and a multimode transmitter. The multimode receiver includes a shared receiver front-end, a receiver multiplexor, and a plurality of receiver IF stages. The multimode transmitter includes a shared transmitter front-end, a transmitter multiplexor, and a plurality of transmitter IF stages.

Abstract: A clock signal recovery circuit that is implemented in a receiver of a universal serial bus (USB) and a method for recovering a clock signal. The clock signal recovery circuit comprises a phase detector, a bidirectional shift register, a multiphase clock signal generator, and a phase selector. The phase detector detects a difference in phases between received data and a predetermined recovery clock signal and generates a first control signal indicative of the detected phase difference. The shift register is shifted in response to the detected signal and outputs a second control signal.

Abstract: A vestigial-sideband (VSB) signal is converted to a double-sideband amplitude-modulation signal having information that is subsequently detected in the double-sideband amplitude-modulation signal. A method for performing the conversion includes mixing the VSB signal with a first beat frequency different from a carrier frequency of the VSB signal, the first beat frequency being of such value as to generate a first mixing result that is translated in frequency to have a carrier at an offset frequency; mixing the VSB signal with a second beat frequency different from the carrier frequency of the VSB signal and from the first beat frequency, the second beat frequency being of such value as to generate a second mixing result that is translated in frequency to have a earner at the offset frequency; and combining the first and second mixing results to form the double-sideband amplitude-modulation signal with a carrier frequency at the offset frequency.

Abstract: An apparatus and method for eliminating a vestigial sideband (VSB) pilot tone in a vestigial sideband/quadrature amplitude modulation (VSB/QAM) receiving system, is provided. This apparatus eliminates a vestigial sideband (VSB) pilot tone in a vestigial sideband/quadrature amplitude modulation (VSB/QAM) shared receiving system including a VSB/QAM shared modulator for demodulating a received VSB signal and outputting I-axis VSB symbols and Q-axis VSB symbols.

Abstract: The system for recovering symbol timing offset and carrier frequency error from an orthogonal frequency division multiplexed (OFDM) signal includes a receiver circuit for receiving an OFDM modulated signal representing a series of OFDM symbols, and providing a received signal to an output thereof. A peak development circuit is included for developing a signal having a plurality of signal peaks representing symbol boundary positions for each received OFDM symbol, where each of the signal peaks is developed responsive to an amplitude and phase correspondence produced between the leading and trailing portions of each of the received OFDM symbols. The system includes a circuit for enhancing the signal peak detectability, which includes a circuit for additively superimposing and then filtering the signal peaks, to produce an enhanced signal peak having an improved signal-to-noise ratio.

Abstract: A vestigial sideband/quadrature amplitude modulation (VSB/QAM) receiver, which receives both VSB and QAM signals and restores a carrier wave with a restored symbol clock after restoring a symbol timing in a front portion of a carrier wave restoration unit.

Abstract: A method of channel estimation in a Code Division Multiple Access (CDMA) transmission system that incorporates Pilot Symbol Assisted Modulation (PSAM) using an iterative coherent detection method to estimate the phase and frequency of the received pilot symbols. Arctangent calculations are used to estimate phase and frequency. An iterative least squares linearization identifies and corrects values of the arctangent associated with an incorrect 2? alias, which arise due to the multiple-valued nature of the arctangent function. An alternative non-iterative least squares linearization also corrects the arctangent values, based on a calculation involving stored values of the pilot symbols.

Abstract: A digital TV receiver and a method for receiving a digital TV signal are disclosed, in which timing recovery and segment synchronizing signal recovery are independently implemented and VSB demodulation is digitally implemented.

Abstract: A method of processing an AM radio signal comprises the step of receiving an AM radio signal including an upper sideband portion and a lower sideband portion, demodulating the upper sideband portion and the lower sideband portion to produce a demodulated upper sideband signal and a demodulated lower sideband signal, weighting the demodulated upper sideband signal and the demodulated lower sideband signal in response to noise power to produce a weighted demodulated upper sideband signal and a weighted demodulated lower sideband signal, and combining the weighted demodulated upper sideband signal and the weighted demodulated lower sideband signal to produce an output signal. Demodulators which process AM radio signals in accordance with the method, and receivers incorporating the demodulators, are also included.

Abstract: A self-powered microthermionic converter having an internal thermal power source integrated into the microthermionic converter. These converters can have high energy-conversion efficiencies over a range of operating temperatures. Microengineering techniques are used to manufacture the converter. The utilization of an internal thermal power source increases potential for mobility and incorporation into small devices. High energy efficiency is obtained by utilization of micron-scale interelectrode gap spacing. Alpha-particle emitting radioisotopes can be used for the internal thermal power source, such as curium and polonium isotopes.

Abstract: Improved carrier recovery and symbol timing systems and methods suitable for use in connection with a dual-mode QAM/VSB receiver system is disclosed. Carrier and symbol timing acquisition and tracking loops are phase/frequency locked to an inserted pilot signal provided in an input VSB spectrum at a given frequency. An input spectrum is centered about baseband and the pilot is extracted by an equivalent filter which functions as a bandpass filter having pass bands centered about the pilot frequency. Since the pilot signal's frequency is given, its position in the frequency domain for any sampling frequency, is deterministic. The receiver's sampling frequency is provided such that the relationship is expressed as fc=fs/4. When tracked by a phase-lock loop, the pilot signal will appear at the correct location in the spectrum if the sampling frequency fs is correct, and will be shifted in one direction or the other if the sampling frequency fs is too high or too low.

Abstract: A vestigial-sideband (VSB) signal is down-converted to generate a VSB signal including a carrier frequency offset from zero frequency by an amount greater than the bandwidth of the VSB signal. The carrier of this final I-F signal has a carrier offset from zero-frequency, which carrier offset exceeds the highest modulating frequency of the VSB signal and is adjusted to a prescribed carrier offset value. The down-converted VSB signal is digitized to generate a digital multiplicand signal for a digital multiplier circuit. The digital multiplier circuit is supplied a digital multiplier signal descriptive of a system function composed of a constant term and a second harmonic of the carrier frequency offset from zero frequency. Digital product signal from the digital multiplier circuit is descriptive of a double-sideband amplitude-modulation final I-F signal in the digital regime, which DSB AM final I-F signal is subsequently detected to generate a baseband demodulation result.

Abstract: An apparatus and method of detecting whether the carrier frequency is locked for confirming recovering carrier is normally performed is disclosed. The apparatus includes a lock detector for judging whether the carrier frequency is locked by extracting DC value form real number component and imaginary component of an OQAM signal, and comparing the accumulated DC value to set value.

Abstract: Improved carrier recovery, symbol timing, and carrier phase tracking systems and methods suitable for use in connection with a dual-mode QAM/VSB receiver system are disclosed. Carrier and phase recovery systems operate on complex signals representing symbols having the same time stamp for each phase error term. in-phase signals are sampled twice a symbol at the in-phase symbol sampling time and at the quadrature-phase symbol sampling time. The signals are de-multiplexed to generate I and XI data streams, where I represents the in-phase sampling time signals and XI represents mid-symbol point sample times. A similar procedure is carrier out on quadrature-phase signals. When the in-phase signal is de-multiplexed to generate a symbol I, the quadrature-phase signal is de-multiplexed to generate its mid-symbol point XQ. Both I and Q are decoded in a decision device to define a symbol error term, which is combined with the opposite mid-symbol signal to define a phase error term PI and PQ for each rail.

Abstract: A tuning system and a tuning method in a broadcast signal receiver, in which a radio frequency (RF) spectrum signal adopting an inverting method is filtered by an asymmetric bandpass filter of a tuner to improve the receiving sensitivity. This tuning system includes a first mixer, a filter and a second mixer. The first mixer mixes a predetermined oscillation frequency with an inverted 8 VSB digital broadcast signal in the idle space between upper and lower normal NTSC broadcast signals of high frequency band received from a transmitter, transfers the upper NTSC broadcast signal to the lower side and the lower NTSC broadcast signal to the upper side, inverts the transferred NTSC broadcast signals, and changes the state of the 8 VSB digital broadcast signal into a normal state. The filter attenuates the inverted upper and lower NTSC broadcast signals output from the first mixer to a predetermined band and amplifies the normal 8 VSB digital broadcast signal into a predetermined band.

Abstract: A format converting apparatus for a mutual data exchange between an IEEE 1394 serial bus and a VSB remodulator is disclosed. The present invention allows a conversion from a format of the IEEE 1394 to the VSB remodulator and also a conversion from a format of the VSB remodulator to the IEEE 1394. Therefore, digital equipment having both the IEEE 1394 and the VSB remodulator can be utilized without problem.

Abstract: Carrier signals are modulated by information (e.g., television) signals in a particular frequency range. The information signals are oversampled at a first frequency greater than any of the frequencies in the particular frequency range to provide digital signals at a second frequency. The digital signals are introduced to a carrier recovery loop which provides a feedback to regulate the frequency of the digital signals at the second frequency. The digital signals are introduced to a symbol recovery loop which provides a feedback to maintain the time for the production of the digital signals in the middle of the data signals. The gain of the digital signals is also regulated in a feedback loop. The digital signals are processed to recover the data in the data signals. By providing digital feedbacks, the information recovered from the digital signals can be quite precise. In one embodiment, the carrier signals are demodulated to produce baseband inphase and quadrature signals.

Abstract: A robust data extension added to a standard 8VSB digital television signal is used to improve the performance of a digital television receiver. The robust data extension is added to a standard 8VSB digital television transmission system by encoding high priority data packets in a rate ½ trellis encoder. The high priority data ½ trellis encoded packets are then multiplexed with normal data packets and input into the normal data service of an 8VSB system, which further contains a rate ⅔ trellis encoder. The combined trellis encoding results in a rate ⅓ trellis encoding for robust data packets and a rate ⅔ trellis encoding for normal packets. Backward compatibility with existing receivers is maintained for 1) 8VSB signaling, 2) trellis encoding and decoding, 3) Reed Solomon encoding and decoding, and 4) MPEG compatibility.

Abstract: A receiver for processing a VSB modulated signal containing terrestrial broadcast high definition television information and a pilot component includes a carrier recovery network (22; FIG. 3) that produces a demodulated baseband signal. The carrier recovery network additionally responds to a locally generated control signal (Ph. Offset; 360) representing an unwanted phase offset of the pilot signal due to multipath distortion, for example. The control signal is used to compensate for the pilot phase offset before the demodulated signal is equalized. The control signal is produced by correlating received sync values with both a reference sync value (362) and a Hilbert transform of the reference sync value (363). The output of the carrier recovery network signal is phase compensated twice.

Abstract: A vestigial-sideband (VSB) signal is converted to a double-sideband amplitude-modulation final intermediate-frequency signal that is subsequently detected to generate a baseband demodulation result. The carrier of this final I-F signal has a carrier offset from zero-frequency, which carrier offset exceeds the highest modulating frequency of the VSB signal and is adjusted to a prescribed carrier offset value. The double-sideband amplitude-modulation final I-F signal is generated by combining the VSB signal with its image.

Abstract: VSB reception system with a frequency domain equalizer including a demodulating part for receiving, converting, and demodulating a signal, a frequency domain equalizing part for equalizing the demodulated signal for removing a distorted component from the demodulated signal, and a noise removing part for (a) receiving the equalized signal, (b) calculating a reference error signal that is a difference between the equalized signal and the signal having the noise removed therefrom, (c) calculating an error signal that is a difference between the reference error signal and the extracted noise signal, (d) renewing parameters with reference to the reference error signal and the error signal, and (e) calculating a difference between the equalized signal and the extracted noise signal, to provide a signal having the noise removed therefrom.

Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams respectively.

Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams respectively.

Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams respectively.

Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams respectively.

Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal pints of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams respectively.

Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams respectively.

Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams respectively.

Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram expressed at least in the polar coordinate system. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into low and high frequency band components which are designated as first and second data streams respectively.