Abstract: It is to provide a multi-signal generator which is able to lower the cost thereof by performing modulation in a low frequency range and using an output of a frequency synthesizer commonly to all channels. The multi-signal generator for generating a multi-signal which is a combination of a plurality of output signals generated by a plurality of channels each of which is using a frequency conversion method wherein a modulated carrier signal and a local signal are frequency converted by a mixer, wherein an output frequency from at least one frequency synthesizer is commonly used as a frequency source for the carrier signal or local signal by all the channels.

Abstract: A double mode modulator, particularly, for a portable telephone, which is adapted to realize both digital and analog modulations and have a low phase noise and a reduced locking time with a device readily integrated in an integrated circuit, including: a frequency synthesizer for synthesizing a particular frequency from an external reference clock signal; a digital modulator for performing a quadrature modulation for an output signal of the frequency synthesizer; and an analog modulator for performing a frequency modulation for the output signal of the frequency synthesizer.

Abstract: An electronic apparatus that includes a digital processor (12), a first digital pulse width modulator (304), a second digital pulse width modulator (306), a combining circuit (308), and a load (310). The digital processor (12) produces a first digital signal (314) and a second digital signal (316). The first digital pulse width modulator (304) is responsive to the first digital signal (314), and the second digital pulse width modulator (306) is responsive to the second digital signal (316). The combining circuit (308) is responsive to the first digital pulse width modulator (304) and the second digital pulse width modulator (306). The load (310) is responsive to the combining circuit (308).

Abstract: A radio data communication device that can perform a packet communication with the packet configuration suitable for transmission of a large volume of data in packet communications utilizing a low rate transmission mode and a high rate transmission mode. The transmitter side transmits packets only in a low rate mode or in a high rate mode after transmission in a low rate mode or only in a high rate mode. The receiver side simultaneously demodulates packets in the low rate mode and the high rate mode to detect the synchronous signal for each mode and judges whether or not in which mode the data has been transmitted, thus selecting the successive receive mode.

Abstract: In a radio communication system (100), enhanced communication capability is provided while maintaining standard channel modulation compatibility. At a transmitter (110, 200, 600), a first information signal is generated from data according to a predefined standard modulation scheme (212, 613). A second information signal is generated from data that provides supplemental information to the standard modulated data (213, 616). For transmission, the first and second information signals are combined into a composite signal (214, 619) that represents the first information signal when interpreted according to the predefined standard modulation scheme.

Abstract: A digital baseband modulator having a flexible architecture that is readily adaptible to a variety of digital modulation types is provided. A symbol builder maps the input data to a series of modulation states corresponding to data symbols that are represented as state indexes. A pair of digital filters accepts the state indexes being generated by the symbol builder to provide both up-sampling and filtering functions. The digital filters are implemented using random access memory (RAM) to implement blocks of interpolating look-up multipliers which may be readily configured between fast, normal, and long modes. The filtered output data from the digital filters is provided to a resampler that converts the filtered output data to an output sample rate that corresponds to the sample rate of output DACs and corresponding analog low pass filters.

Abstract: A novel communications method for generating specific unique information containing waveforms, for geometrically modulating a signal with those waveforms, and an apparatus for generating the waveforms, geometrically modulating carrier waves with those waveforms, or broadcasting the novel waves by RF, microwave, electric cable, or fiberoptic conduits.

Abstract: A digital and analog modulator is configured in a simplified circuit structure. The modulator includes a first frequency mixer circuit for modulating a carrier with an analog signal or a sine wave component of a digital signal, a second frequency mixer circuit for modulating a signal attained by shifting a phase of the carrier with an analog signal or a cosine wave component of the digital signal, and an adder for adding signals from the first and second frequency mixer circuits to each other.

Abstract: A multiple access digital up converter/modulator includes selectors (1606, 1608) having inputs (1602, 1604) and outputs coupled to first and second interpolating filters (1610, 1626). The output of the first interpolating filter is selectively coupled to a first mixer (1612) and a first adder (1622), the first adder also receiving a first phase value and the output is coupled to a first phase accumulator (1616) the output of which is coupled to a first sinusoid generator (1614) and selectively coupled to a second sinusoid generator (1630). The output of each of the first and second mixers are selectively coupled to an output adder (1634) and to inputs of the first and second mixers. The output of the second interpolating filter (1626) is selectively coupled to a second mixer (1628) and a second adder (1638), which also receives a second phase value and the output of which is coupled to a second phase accumulator (1640) the output of which is selectively coupled to the second sinusoid generator.

Abstract: In a dual mode transmitter for modulating, in a digital mode, an input digital signal and transmitting a modulated digital signal and modulating, in an analog mode, an input analog signal and transmitting a modulated analog signal, a digital modulating section modulates the input digital signal to thereby generate the modulated digital signal, and outputs the modulated digital signal. An analog modulator/carrier generator modulates the input analog signal to thereby generate the modulated analog signal, and outputs it. Also, the analog modulator/carrier generator generates a carrier signal for up-converting the modulated digital signal. The up-converter up-converts, in the digital mode, the modulated digital signal by using the carrier signal and receives, in the analog mode, the modulated analog signal and passes it therethrough.

Abstract: A dual-mode frequency and phase RF modulator (11) for use in a transmitter of a radiotelephone. A dual-mode modulation approach is employed wherein, in the analog (FM) mode of operation, a phase modulator, such as a .pi./4-shift DQPSK modulator, is bypassed and may be powered down. A frequency modulated RF carrier is coupled through a bypass circuit (52) to a modulator output node (50) for transmission from the radiotelephone. In the digital mode of operation, the bypass signal path is disabled, the .pi./4-shift DQPSK modulator is enabled, and in-phase (I) and quadrature (Q) signals are input to the .pi./4-shift DQPSK modulator which provides a phase modulated RF carrier that is coupled to the modulator output node for transmission from the radiotelephone. The teaching of this invention can be employed with radiotelephones having, by example, TDMA/analog capability or CDMA/analog capability.

Abstract: A high frequency arbitrarily modulated signal and noise generator utilizes digital numerically controlled oscillators providing interbusiness directly to an adder and which are phase modulated. The digital adder feeds a digital analog converter, eliminating the need for a digital multiplier while providing amplitude or phase modulation with high resolution and at high processing speeds.

Abstract: An IQ modulator incorporates a quadrature network that is responsive to a frequency dependent control signal and that has in-phase and quadrature signals that are of equal amplitude and in exact quadrature over a wide range of applied frequencies. The quadrature network includes RC and CR phase shifters whose C's are fixed capacitors of equal value and whose R's are made equal to each other and to the capacitive reactance of the C's by the action of the frequency dependent control signal. The R's may be FET's. The frequency dependent control signal may be generated without express knowledge of the applied frequency by a servo loop that nulls out the amplitude difference between the in-phase and quadrature outputs from the quadrature network; it may also be generated from a look-up table as an express function of frequency. The frequency dependent control signal is split into separate instances that are applied to each R, and an offset may be introduced therebetween to provide extreme precision.

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

Abstract: An FM signal generator generates an FM signal obtained by frequency-modulating a reference frequency signal with a modulating frequency signal. A first mixer mixes the FM signal and an input signal having a predetermined carrier frequency and outputs a pair of frequency signals having sum and difference frequencies thereof. A first signal extracting unit extracts one of the pair of frequency signals as an intermediate frequency signal. A delay circuit delays the extracted intermediate frequency signal by a predetermined time. A second mixer mixes the delayed intermediate frequency signal and the FM signal and outputs a pair of frequency signals having sum and difference frequencies. A second signal extracting unit extracts the frequency signal of the pair of frequency signals which corresponds to the carrier frequency component as a phase-modulated signal. The modulation degree and modulation frequency in phase modulation for the phase-modulated signal can be set in wide ranges.

Abstract: A novel communications method for generating specific unique information containing waveforms, for geometrically modulating a signal with those waveforms, and an apparatus for generating the waveforms, geometrically modulating carrier waves with those waveforms, or broadcasting the novel waves by RF, microwave, electric cable, or fiberoptic conduits.

Abstract: A coefficient circuit 11 multiplies a digitized input modulation signal by a constant and outputs the multiplied signal. Delay circuits 12 and 13 delay the discrete in-phase input signal and discrete quadrature-phase input signal by 1 sampling cycle, respectively. A multiplying circuit 14 multiplies the multiplied signal by the 1-sampling cycle delayed discrete quadrature-phase input signal. The multiplying circuit 15 multiplies the multiplied signal by the 1-sampling cycle delayed discrete in-phase input signal. The adder circuit 16 adds the multiplication results of the multiplying circuit 14 to the 1-sampling cycle delayed discrete in-phase input signal and outputs the addition result as the discrete in-phase input signal. The subtracting circuit 17 subtracts the multiplication results of the multiplying circuit 15 from the 1-sampling cycle delayed discrete quadrature-phase input signal and outputs the subtraction result as the discrete quadrature-phase input signal.

Abstract: A modulation apparatus for a cellular radio system in which capacity is increased and power consumption is minimized, said system covering large and small area cells of different sizes. At least two different modulation schemes are used in the system. For large area cells, constant envelope modulation is used for minimizing power consumption, and for small area cells, linear modulation is used for minimizing the channel spacing, and in this manner, for increasing the cellular capacity.

Abstract: A variable-throughput digital modulator receives at an input a transmission digital signal e(t). The transmission digital signal is time-based demultiplexed (1) into first and second elementary transmission signals e1(t) and e2(t) which are applied, respectively, to first (21) and second (22) filtering circuits for delivering first and second filtered elementary signals e1f(t) and e2f(t). A circuit (20) provides throughput switching control to the first and second filtering circuits (21, 22) for selecting a first or second filtering mode corresponding to a first throughput at a first type of modulation or a second throughput at a second type of modulation. A quadrature modulator (3) receives the first and second filtered elementary signals in order to modulate an RDS-compatible carrier f0, and an output filter circuit (5) delivers a filtered modulated carrier signal for broadcast, such as in supplementary data broadcasting in FM radio broadcasting.

Abstract: Apparatus and a method for generating all of the assignable carrier frequencies in the FM broadcast band and for frequency modulating the generated carriers includes a generator of a train of pulses having a crystal-controlled repetition frequency and a specific pulse shape which together produce a spectrum of odd harmonics of the pulse repetition frequency whose separation in frequency is identical to that of the assignable carrier frequencies. This pulse train is then mixed with a 98.0 MHz sine wave to translate the spectrum to the FM band. Simultaneous modulation of all the carriers is achieved by frequency modulating the 98.0 MHz sine wave, whereby the same modulation is imparted simultaneously to all of the carriers.

Abstract: A novel communication apparatus comprising a transmitter capable of geometrically modulating an existing modulated electromagnetic signal, a method for geometrically modulating a frequency modulated signal, and a receiver for decoding the modulated signal waveform without damaging the underlying harmonic content of the carrier wave and decoding the underlying modulated electromagnetic signal.

Abstract: A dual-mode radiotelephone terminal includes a .pi./4-shift DQPSK modulator (11). A dual-mode modulation is achieved by mixing an output of a transmitter oscillator (16) with an output of an offset oscillator (18) to form an injection signal (LO) at a final transmitter frequency, the injection signal being further modulated with a quadrature modulator in a digital mode of operation. In an analog mode of operation the transmitter oscillator or the offset oscillator is frequency modulated and the quadrature modulator is disabled with a bias signal, thereby passing the frequency modulated injection signal without substantial attenuation. The LO signal is regenerated and also phase shifted with a circuit (35) having a frequency multiplier (30) and a frequency divider (34). The circuit outputs two local oscillator (LO) signals (LOA and LOB), each of which directly drives an associated quadrature mixer (36, 38) of the modulator.

Abstract: A data transmission system includes a source of a data signal and a modulator, responsive to the data signal, producing a first modulated signal representing the data signal and a second modulated signal representing a signal 180 out-of-phase with the data signal. The first and second modulated signals are transported via a transmission channel. A first demodulator demodulates the transported first modulated signal and a second demodulator demodulates the transported second modulated signal. A subtractor, responsive to the first and second demodulators, produces a signal representative of the data signal.

Abstract: A numerically-controlled modulated oscillator and modulation method which selectively provides frequency modulation, phase modulation or amplitude modulation with minimal circuitry. A numerically-controlled modulated oscillator is provided having a tuning register for receiving a center frequency parameter, an adder for receiving at one input the frequency parameter, a phase accumulator for receiving a phase increment number from the adder and producing a waveform phase number, a waveform memory for producing a waveform amplitude number in response to the phase number, and a digital-to-analog converter for producing an analog signal in response to the waveform amplitude number. Another input is provided to the adder from an angle modulation register which provides an angle modulation parameter. This parameter can perform either phase or frequency modulation.

Abstract: Upon transmission, when the digital transmission mode is set, an analog audio signal is A/D converted, the digital audio signal is coded, a first carrier is modulated by the coded signal and multiplied by a first multiplier, and the multiplied signal is sent to an orthogonal modulating and D/A converting circuit. When the analog transmission mode is set, a second carrier is modulated by the digital audio signal and multiplied by a second multiplier, and the multiplied signal is sent to the orthogonal modulating and D/A converting circuit. A signal of a frequency which is equal in both of the digital transmission mode and the analog transmission mode is given to the orthogonal modulating and D/A converting circuit. Upon reception, when the digital transmission mode is set, an output of an A/D converting and orthogonal demodulating circuit is frequency divided by a first frequency divider and demodulated and decoded.

Abstract: A circuit arrangement allows either analog (ANAL) modulation or (DIG) digital modulation to be selected by means of couplers (K1, K2) for transmission over a radio channel. The analog or digital signals are applied to I,Q generators to form I, Q wave shapes (I.sub.A, Q.sub.A or I.sub.D, Q.sub.D), which modulate a possible intermediate frequency in a stage (3) and upon summation, modulate a transmission frequency in a stage (4).

Abstract: Vector modulation is effected by summing output signals from two phase modulators. The lack of amplitude modulation on the signals when summed permits non-linear processing of the signals, such as PLL frequency translation. In one embodiment, the phase modulators comprise fractional-N phase locked loops modulated with digital data words. In another, the phase modulators comprise direct digital synthesizers.

Abstract: In a frequency modulation system, a modulating signal is split into its low-frequency and high-frequency components. The low frequency component is used to modulate a carrier signal by conventional means in a first circuit and the low- and high-frequency components are used to narrowband modulate the carrier signal in a second circuit. The outputs of the first and second circuits are combined to provide a frequency modulated signal. The modulating and carrier signals can be binary-coded signals.

Abstract: In a direct digital synthesizer providing a frequency modulated output the modulation input is bit shifted and the rate of the direct digital synthesizer phase accumulation is controlled to provide enhanced FM deviation resolution.

Abstract: In a circuit arrangement for the generation of I,Q waveforms, an incoming analog signal controls a voltage-controlled oscillator (1), whose output signal (U1) is frequency-modulated. This signal (U1) is mixed with unmodulated signals by using mixers that are switches (6,7). The signals controlling the switches are either modulated or oscillator-generated rectangular waves. The circuit arrangement can be implemented as an integrated circuit.

Abstract: An RF power supply serves to supply a regulated power amplified RF drive signal to an RF transmitter. The supply includes an RF oscillator for providing an RF input signal. A DC voltage source provides a DC voltage V. A plurality of power amplifiers are provided with each receiving the input RF signal and each having an input for receiving a DC voltage signal, and each serving to amplify the input RF signal by an amount dependent upon the magnitude of the DC voltage signal supplied to its input and thereby provide an amplified RF signal. The amplified RF signals are combined to provide an RF drive signal. The DC voltage V is directly supplied to the input of at least a first one of the power amplifiers.