Abstract: Herein disclosed is a wireless microphone for receiving a sound signal and transmitting a radio signal and operable in combination with an acoustic operation unit to output a control signal, comprising: modulating means for modulating the radio signal with the sound signal to produce a modulated radio signal, the modulating means being operative under a plurality of operation conditions and having a plurality of signal channels in association with the operation conditions allowing the modulated radio signals to pass therethrough; detecting means for detecting the control signal outputted by the acoustic operation unit, the control signal being indicative of the operation conditions of the modulating means; and adjusting means for adjusting the operation conditions of the modulating means in response to the control signal from the acoustic operations unit.

Abstract: A search and rescue beacon includes a main transmitter transmitting a Cospas-Sarsat signal at a main frequency and an auxiliary homing transmitter transmitting a homing signal at a homing frequency close to the main frequency. Advantageously both the Cospas-Sarsat signal and the homing signal are generated by a single synthesizer switching between a main Cospas-Sarsat burst transmission and a continuous homing frequency transmission of the homing signal. The Cospas-Sarsat signal is advantageously transmitted at a higher power than the homing signal. The single synthesizer may use a single amplifier chain. The single synthesizer and amplifier chain may use a single antenna.

Abstract: A structure for preventing intermodulation interference in satellite transmission is characterized in that a frequency subtraction is executed at a first mixer and a local oscillator on one of the received satellite vertical and horizontal polarized signals to obtain a first mid-band, while a frequency subtraction is executed at a second mixer and a first-stage local oscillator on the other received signal to obtain a reverse-phase signal thereof, and a frequency addition is executed at a third mixer and a second-stage local oscillator on the reverse-phase signal to obtain a second mid-band, and that second and third harmonic differences between a frequency obtained by subtracting the oscillating frequency of the second-stage local oscillator from the oscillating frequency of the first-stage local oscillator and the oscillating frequency of the local oscillators do not fall in the first and the second mid-bands, respectively, and an intermodulation interference is prevented.

Abstract: A transmitter (1) converts an input signal from a microphone (2) into a plural-bit digital signal by means of an A/D converter (4) at predetermined time intervals. An encoder (6) divides the digital signal into plural blocks and adds a parity bit to each block to thereby form a coded signal. A transmitting unit (8) modulates a carrier with the coded signal and transmits the modulated carrier through an antenna (10). A receiver (12) includes two tuning units (18A, 18B). Corresponding coded signals outputted from the tuning units (18A, 18B) are inputted to a decoder (20). The decoder (20) makes a parity check on respective blocks of the corresponding coded signals and selects and outputs an error-free one of the corresponding blocks of the corresponding coded signals.

Abstract: A CDMA PCS telecommunications cell (40) of increased capacity includes a plurality of sectors (42, 44, 46) controlled by a base station (14) using a defined set of CDMA codes for each sector. Capacity is increased by configuring the base station to operate at two different, non-interfering frequencies within each sector of the cell.

Abstract: The present invention is directed toward the transmission subsystem of a multi-mode, multi-band communication system that can transmit and/or receive one or more information signals on one or more transmission frequencies using one or more modulation schemes. According to embodiments of the invention, the up-conversion section is implemented using a universal frequency translator (UFT).

Abstract: Disclosed is a communication apparatus having a small-scale circuit used for modulation. A common transmission image rejection mixer (56) supplies transmission modulation frequencies to a plurality of quadrature modulators (23) (G, D, P, W). Accordingly, it is unnecessary to prepare the transmission image rejection mixer (56) for transmission signal types, makes it possible to prevent the circuit scale from increasing.

Abstract: The present invention provides power amplification circuitry having multiple amplifier stages in series and adapted to facilitate polar modulation. As such, the amplifier circuitry receives a frequency signal representing the frequency and phase components of the signal to be transmitted, as well as an amplitude signal presenting the amplitude component of the signal to be transmitted. The frequency component is amplified by the amplification circuitry. The amplitude component controls the supply voltage provided to the amplifier stages in the amplification circuitry. To increase the dynamic range of the amplification circuitry, the final stage or stages of the amplification circuitry are selectively disabled when lower output powers are necessary, and enabled when higher output powers are required.

Abstract: Methods and apparatus are presented to provide transmit diversity gains to non-transmit diversity configured remote stations by correlating the magnitude of the interference between at least two antenna paths. A first time-varying transformation is applied to a stream of modulation symbols to form a first transmission signal and a second time-varying transformation is applied to the stream of modulation symbols to form a second transmission signal, wherein the second time-varying transformation has a different relative phase from the first time-varying transformation.

Abstract: A wireless transceiver includes a transmitter having a harmonic rejection mixer and an RF output phase-locked loop in a two step up-conversion architecture, and a direct conversion receiver. The transmitter includes a local oscillator for producing a signal at a multiple of an intermediate frequency, a quadrature modulator harmonic rejection mixer responsive to the signal at the multiple of the intermediate frequency for modulating in-phase and quadrature-phase base-band signals to produce an intermediate frequency signal, a filter responsive to the intermediate frequency signal for producing a filtered intermediate frequency signal, and an RF output offset phase-locked loop responsive to the filtered intermediate frequency signal and the signal at the multiple of the intermediate frequency for producing an RF transmission signal. The harmonic rejection mixer reduces filtering requirements to facilitate a high level of circuit integration.

Abstract: A signal having one of a plurality of modulation formats is formed by encoding first data in accordance with a particular one of the modulation formats. The encoded first data is then combined with second data identifying the particular modulation format of the encoded first data to form the signal.

Abstract: A transmitter adopting a polar loop system including a phase control loop for controlling the phase of a carrier signal outputted from a transmitting oscillator and an amplitude control loop for controlling the amplitude of a transmitting output signal outputted from a power amplification circuit, and designed to be capable of performing transmission using a GMSK modulation mode and transmission using an 8-PSK modulation mode. In the transmitter, the phase control loop is shared as a phase control loop for use in the GMSK modulation mode and a phase control loop for use in the 8-PSK modulation mode. A component similar to any one of components constituting a loop filter is provided in parallel therewith so that the component can be connected or disconnected in accordance with the modulation mode, for example, by use of a switching element.

Abstract: Transmitter systems in which an output signal is obtained by the summation of signals with predetermined discreet levels given by several amplification cells. Given a signal to be sent with an amplitude A and a phase &phgr;0, a control circuit determines (&agr;) a number of amplification cells sufficient to obtain slightly more than the value A with the phase &phgr;0 but to carry out a phase adjustment (&bgr;) such that at least two of the cells are phase-shifted, one in advance and the other delayed with respect to &phgr;0, so that the total sum of the signals delivered by the cells gives the signal A, &phgr;0. Such transmission may find particular application to amplification cell transmitters with discrete output levels.

Abstract: The invention is a radio transmitter and a method for transforming digital amplitude as well as phase or frequency modulation information into analog signals for controlling analog amplifier circuitry. The method includes providing first and second digital signals representing phase angle; converting the signals into analog signals; mixing the analog signals with oscillator signals to obtain an analog, modulated signal; providing a third digital signal corresponding to amplitude; converting this signal into an analog signal; and feeding the analog, modulated signal and said analog signal to the analog amplifier circuitry.

Abstract: A dual modulation transmitter apparatus (100) includes first (134), second (136), and third (132) signal paths. The first signal path includes a polar modulator (120) coupled to a data input (115). The second signal path includes a quadrature modulator (122) coupled to the data input. The third signal path is coupled to an antenna (142) and includes a switch (128) configured to couple the third signal path to the first signal path under a first condition and to couple the third signal path to the second signal path under a second condition. Thus, the transmitter apparatus enjoys the best of both worlds, since it utilizes quadrature or polar modulation in the most appropriate circumstances.

Abstract: A system for using a translation loop upconverter and power amplifier including a secondary phase-error correction loop uses the output of the upconverter to lock a feedback loop during a time in which the output of the power amplifier is insufficient to provide feedback to the upconverter. After the power amplifier has developed sufficient power to provide feedback to the upconverter, the feedback to the upconverter is taken from the output of the power amplifier. By placing a phase detector and phase shifter in the secondary feedback path taken from the output of the power amplifier, any phase distortion present in the system can be detected and corrected.

Abstract: A complete process is described for demodulating subsidiary communications authorization (SCA) radio signals. This process takes as an input an FM radio signal from a commercial FM telescoping type antenna. The signal is optimally processed through filtering, amplification, and dual detection circuitry to provide a high quality sub-carrier audio signal. Special matching is provided to set the signal's gain, noise figure, and injected distortion levels as a function of the antenna being extended or collapsed. Also, filtering of RF image and IF baseband signals is uniquely and efficiently performed in a radio receiver having an telescoping antenna and audio out line, an SCA radio turner has a matching filter between the antenna and a first FM discriminator to match the level of extension of the antenna, a phase-lock-loop circuit within a second FM discriminator following the first FM discriminator, and sub-carrier audio processing between the FM discriminator and the audio out line.

Abstract: The present invention includes a system and method for ensuring reception of a communications signal. A modulating baseband signal with desired information is accepted, and a plurality of redundant spectrums is generated. Each redundant spectrum comprises the necessary amplitude, phase, and frequency information to substantially reconstruct the modulating baseband signal. It is expected but not required that the redundant spectrums will be generated at a first location and sent to a second location over a communications medium. At the second location, the redundant spectrums are independently processed to recover a demodulating baseband signal for each of the redundant spectrums. In one embodiment, an error detection process is employed at the second location to detect and eliminate those demodulated baseband signals that have been corrupted during transmission. An error-free demodulated baseband signal is selected from the remaining demodulated baseband signals.

Abstract: A control system for a linear feed-forward amplifier, using the ratio of measured spurious energy. Measuring receivers are coupled to two monitoring points to measure the spurious energy content in the error signal and at the main output of a feed-forward amplifier. The control system measures the ratio of these detected spurious, and uses this to optimize the settings of the second loop distortion cancellation. With the addition of an extra monitoring point, the same technique may also be used to control an adaptive predistorter prior to the main amplifier.

Abstract: A method and apparatus for radio communication are presented. The method employs an antenna having multiple transceivers, each capable for receiving a part-signal of a signal received by the antenna. The phase and amplitude of the part-signals are modulated with a code that corresponds to the part-signal. The part-signals are then digitally processed using an analog-to-digital converter, and then demodulated with a demodulation code that is an inverse of the modulation code. The demodulated signal is then divided into separable part-signals which correspond to different reception patterns of the antenna.

Abstract: A system for locally broadcasting audio content is described, comprising: a multimedia recording apparatus having a mass storage device for storing audio content; a content selection module to select specific audio content from the mass storage device responsive to a user input; a decoder to decode the specific audio content using a specified decoding algorithm; a frequency modulation (“FM”) and/or amplitude modulation (“AM”) modulator to frequency-modulate and/or amplitude-modulate, respectively, the specific audio content; and a transmitter to broadcast the modulated specific audio content below a threshold broadcast power level and at a specified carrier frequency.

Abstract: Channel estimation is performed for a received signal, wherein different parts of the received signals are modulated using different modulation types. The channel is first estimated based on part of a received signal modulated with a first modulation type. This channel estimate is then transformed into a channel estimate corresponding to at least a second modulation type.

Abstract: A communications device includes an amplifier module configured to amplify a signal. The amplifier module includes a parallel arrangement of amplifiers each designed to operate with increased efficiency for different power level ranges. A controllable switch selectively interconnects the power amplifiers. A controller in communication with the controllable switch selectively interconnects the power amplifiers to increase the efficiency of the amplifier module.

Abstract: A transmitter for improving the spectral characteristics of a transmitted output signal includes a phase modulator for receiving a signal and modifying the phase of the signal, a power amplifier for receiving the phase modified signal from the first operation and amplifying the phase modified signal, and an amplitude modulator for receiving the amplified phase modified signal and modifying the amplitude of the amplified phase modified signal. Although the phase and amplitude modulation are performed separately in order to minimize the amplitude distortion without complicating the design of the phase modulator, the combined effect of the phase and amplitude modulation is to filter the out of band spectral emissions of the transmitted output signal.

Abstract: Communications method including the procedures of modulating a second generation carrier signal, with a first generation Baseband bandwidth signal, when transmitting to first generation devices, and, modulating the second generation carrier signal, with a second generation Baseband bandwidth signal, when transmitting to second generation devices, wherein the frequency of the second generation carrier signal, is an integer multiple of the first generation Baseband bandwidths, away from a first generation carrier signal frequency.

Abstract: In a wireless transmission system that transmits the same information in parallel using two or more different types of modulation schemes, such as a satellite-based digital audio transmission system transmitting two TDM signals and a single OFDM signal, a receiver processes the differently modulated signals to generate separate demodulated signals that are then combined to form a single combined signal for further processing (e.g., decoding). In one embodiment, the receiver applies a maximal ratio combining (MRC) technique to generate a single optimal ratio combined signal from the differently modulated signals. By combining the differently modulated signals using an MRC technique, the adverse affects of noise related to inter-symbol interference in the individual signals can be reduced and the complexity of hardware in the receiver can be reduced.

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 system and method for transmitting digital information through a medium such as atmospheric free-space includes a transmitter which generates a signal based on a basis set of mutually orthogonal, spectrally-shaped, sequences of substantially equal length and having predetermined autocorrelation values. The sequences may resemble noise in at least some of their characteristics. The orthogonality or cross-correlation characteristics, the autocorrelation characteristics and the resemblance to noise are due to features derived from sequences of pseudo-random numbers which themselves resemble noise in at least some of their characteristics. The waveform set based on the sequences is modulated digitally. The modulated set may be summed together along with a wideband reference signal of reduced amplitude and optionally an FM analog signal to form a composite signal which is broadcast typically through free space to at least one receiver.

Abstract: A new modulation/demodulation method and apparatus are described for use with RF communication. A transmitter (1001T) modulates information onto a plurality of carrier signals transmitted simultaneously over a corresponding plurality of frequencies using cepstral modulation. A receiver (1003R) receives the plurality of carrier signals and demodulates the signals utilizing cepstral demodulation. Receiver (1003R) monitors the carrier signals and in response to predetermined conditions selects a cepstral constellation to be utilized. Receiver (1003R) provides the cepstral constellation information to a transmitter (1003T) that, in turn, transmits the cepstral constellation information to a receiver (1001R), in turn, provides the cepstral constellation information to transmitter (100T). Transmitter (1001T) utilizes the selected cepstral constellation information to modulate the next transmission of the plurality of carrier signals.

Abstract: A multi-rate data modulation circuit includes a multi-rate data conversion circuit and a modulator such as a direct digital synthesis circuit. The multi-rate data conversion circuit receives digital data at varying data rates, receives a data rate input corresponding to the digital data and converts the digital data to a converted output based upon the data rate input. The direct digital synthesis circuit receives the converted output and synthesizes a modulated output signal based upon the converted output. The multi-rate data conversion circuit may include a multi-rate converter, a multi-rate digital data filter, an output scaler and an adder. The multi-rate converter receives the digital data, the data rate input and a clock signal and converts the digital data to converted digital data. The multi-rate digital data filter receives the converted digital data and produces a filtered digital output. The output scaler receives the filtered digital output and produces a scaled and filtered digital output.

Abstract: A single base station supports the non-diversity transmission of a first digital signal type and the diversity transmission of a second digital signal type. The base station includes primary channel boards for modulating and encoding a first digital signal type and secondary channel boards for modulating and encoding a second digital signal type. A first group of transmit radio modules accept the first digital signal type and the second digital signal type and provides a composite electromagnetic output signal. Each transmit radio module is associated with a different sector. A second group of transmit radio modules accept the second digital signal type from secondary channel boards and provide a diverse electromagnetic output signal for complementing the composite electromagnetic output signal.

Abstract: A narrow bandwidth signal, such as a narrowband FM signal, is modulated in a modulator that modulates a wide bandwidth signal, such as a CDMA signal, by oversampling the narrow bandwidth signal and applying the oversampled narrow bandwidth signal to the modulator. By oversampling the narrow bandwidth signal, the same fixed low pass filter can be used for both the wide bandwidth signal and the oversampled narrow bandwidth signal. Accordingly, different low pass filters or switched low pass filters are not needed. The DC offset that is introduced by the digital-to-analog converter and/or the low pass filter of the modulator is compensated, preferably in the digital domain, to thereby reduce DC offset within acceptable limits for the modulation that is being used. More preferably, compensation is provided by subtracting from the sampled signal, a digital value representing the DC offset in the filtered analog signal that is introduced by the digital-to-analog converter and/or the low pass filter.

Abstract: A radio frequency power amplifier (16) for use in at least 2 frequency bands, comprises a power amplifier (32) having a passive adjustable input matching network (30), a passive variable output power matching network (34, 36) and a source (48) of tuning voltages for adjusting the input and output networks so that the power amplifier functions as a narrowband amplifier in a predetermined one of the at least 2 frequency bands. The source of tuning voltages may comprise a look-up table.

Abstract: A method and system is described wherein a signal with a lower frequency is up-converted to a higher frequency. In one embodiment, the higher frequency signal is used as a stable frequency and phase reference. In another embodiment, the invention is used as a transmitter. The up-conversion is accomplished by controlling a switch with an oscillating signal, the frequency of the oscillating signal being selected as a sub-harmonic of the desired output frequency. When the invention is being used as a frequency or phase reference, the oscillating signal is not modulated, and controls a switch that is connected to a bias signal. When the invention is being used in the frequency modulation (FM) or phase modulation (PM) implementations, the oscillating signal is modulated by an information signal before it causes the switch to gate the bias signal.

Abstract: The present inventions provide methods and systems for reducing the peak to average power ratio of a multi-carrier signal. Reducing the peak to average power ratio of a signal ensures that amplifiers and transmitters are not saturated, causing loss of data. Further, reducing peak to average power ratios reduces the consumption of power during transmission. Peak to average power ratios are reduced by applying a peak reduction signal component to one or more of the plurality of information signals that make up the multi-carrier signal. In one embodiment the peak reduction signal is a basis function of the communication system. The information signal is mapped to duplicate constellation points, which may be easily decoded by a receiver by performing a modulo operation. Negation of the peaks may be performed iteratively to remove any peaks produced during prior peak reduction operations.

Abstract: A circuit configuration for direction modulation contains an oscillator, whose output signal is split into quadrature components for modulation with a useful signal. A frequency shifting circuit has the effect that that the output frequency and the frequency of the oscillator are fractional rational multiples with respect to one another. The circuit contains a phase shifter for generating first further quadrature components and also a divider for generating second further quadrature components. The quadrature components are mixed with one another. As a result of the frequency offset, the oscillation frequency of the oscillator is shifted to outside the useful frequency band. Remodulation effects do not influence the adjacent channels. The circuit can be realized simply and cost-effectively and, in particular, requires only one oscillator.

Abstract: A transceiver (10) includes a transmitter (16) that receives a digital data stream from a digital signal processor (18) to delay lines (20, 30). The delay lines (20, 30) provide an address to a ROM look-up table (40). Another input of the look-up table (40) receives a signal that selects protocols such as TDMA, CDMA, and GSM. A multi-accumulator fractional-N synthesizer (48) receives phase derivative coefficients and a DAC (46) receives amplitude modulation coefficients from the look-up table (40) based on the selected protocol. The analog output signals from the DAC (46) and the synthesizer (48) are received by a variable gain amplifier (54) that generates an RF amplitude and frequency modulated output signal for transmission from the transmitter (16).

Abstract: Transmitting systems and methods for multiple access protocols consistent with the present invention include device(s) to increase data rates in at least two portions that generate different access protocols. The increased data rates cause noise generated by &Sgr;-&Dgr; converters in the at least two portions to occupy high frequencies, enabling the at least two portions to share common reconstruction filters. Shifting the noise in such a manner also allows the use of wide bandwidth common reconstruction filters.

Abstract: A switching system to multiple transceivers in a mobile computing system allows communication through various technologies, namely belonging to WWAN, WLAN, and WPAN space. A common antenna or antennas is shared by the transceivers. The switching system connects the proper transceiver to the antenna system and communication priority to and from the computer system is given to the chosen transceiver. The transceivers are placed on a Mini PCI card or similar factor form and interface directly to the computing system. Transceiver priority may be chosen by a particular application or when communication is being sent to the system, the proper transceiver may be chosen to receive the communicated signals.

Abstract: In a digital wireless audio transmission system, a transmitter section includes a local oscillator and frequency modulator to modulate the local oscillator signal with a periodic transmitter spreading signal in order to generate a frequency-modulated radio-frequency signal. An amplitude modulator amplitude-modulates this signal with serial digital data that is generated by an audio interface and a channel encoder. This amplitude-keyed signal which is spread in frequency is then transmitted via a transmit antenna as electromagnetic waves. A receiver section receives these electromagnetic waves via multiple antennae and amplitude-modulates the signal of at least one antenna with antenna modulator signals that have the same frequency as the transmitter spreading signal and a fixed relative phase deviation. All of these antenna signals are then added, and the sum signal is amplified and detected by a small-signal detector.

Abstract: The invention relates to a method for reducing interference in radio transmitters with feedback from the antenna end to the baseband side and to a transmitter applying the said method. In a Cartesian loop formed for the linearization of a transmitter, the levels of baseband input signals (sI2, sQ2) to a modulator are measured and the attenuation of a level control unit (210) following the modulator (203) is adjusted until the modulator input signal levels are sufficiently above the noise level. The adjustment may be carried out as a one-time procedure during the manufacturing process or repeatedly during the operation of the device. By means of the invention, the noise level of the output signal of a linearized transmitter can be made lower than in known transmitters. Moreover, the transmitter may utilize a cheaper and, from the point of view of manufacturing, easier 4modulator than known transmitters.

Abstract: A method and system for blind detection of modulation in a wireless telecommunications network. In accordance with the method and system, a plurality of bursts are transmitted over an air interface to a receiving station using a first modulation scheme. Modulation detection statistics for the plurality of received bursts are calculated at the receiving station. Based on the modulation statistics, however, it is determined that at least one of the plurality of received bursts has been transmitted using a second modulation scheme. As a result, the modulation detection statistics are analyzed to identify a single modulation scheme that was most likely used in modulating the plurality of bursts. Any faulty received bursts, for which a detected modulation scheme differs from the identified single modulation scheme, are then processed to reduce the effect of the faulty bursts.

Abstract: An apparatus for forming a beam in a base station is provided and includes a plurality of channel cards for processing and outputting signals to be transmitted to each channel; a signal synthesizer/distributor for synthesizing the signals from the channel cards and compensating phases of the signals; a channel controller for controlling beams of the signals from the signal synthesizer/distributor according to a demand of a mobile communication terminal and outputting the controlled beam signals; a middle frequency generating block for receiving the signals from the channel controller and synthesizing the signals in each frequency to generate middle frequency signals; a transmitter for converting the middle frequency signals received from the middle frequency generating block into signals in a transmitting band; an RFB for amplifying the signals from the transmitter into signals in an output band and controlling phases of transmitting and receiving signals; and an antenna connection block for switching the sig

Abstract: A data transmission method and system for circuit switched and other services that can be employed in TDMA-based systems, and that supports the use of one or several types of modulation (e.g., 8-PSK modulation), in addition to a “normal” modulation (e.g., GMSK modulation) on a radio interface. An additional modulation/channel coding (e.g., one based on 8-PSK) may be used in the downlink transmission, while the normal modulation/channel coding (e.g., one based on GMSK) may be used in the uplink transmissions, under a variety of different conditions. A first condition arises where the radio conditions allow the use of the additional modulation in both directions, but the mobile station transmitter does not support it. A second condition arises where the radio conditions allow the use of the additional modulation in both directions, and the mobile station supports it, but the user requests a downlink-biased or uplink-biased data transmission service.

Abstract: A transmission circuit includes first and second amplifiers, a bandpass filter, a phase adjuster, and a signal combiner. The first and second amplifiers independently amplify input signals in different transmission frequency bands. The first amplifier in the ON state produces an unnecessary radiant wave in a frequency band substantially coinciding with the transmission frequency band of the second amplifier in the OFF state. The bandpass filter extracts a component in the same frequency band as that of an unnecessary radiant wave leaking out from the second amplifier during operation of the first amplifier. A phase adjuster adjusts the phase of an output signal from the bandpass filter such that the phase of the output signal from the bandpass filter becomes opposite to that of an unnecessary radiant wave in an output signal from the first amplifier. The signal combiner combines an output signal from the phase adjuster with the output signal from the first amplifier.

Abstract: A dual mode wireless device in which a coefficient generator (42) generates parameter values for a GSM waveform, based on transmitted sequences of digital data values from a GSM unit (34), using a multiplierless operation, and a waveform generator 44 generating the GSM waveform using the generated parameter values. The coefficient generator includes adder sections (132, 134, 136), each having corresponding adders (142, 144, 146) and multipliers (148, 150, 152), register sections (154, 156, 158), each containing parameters corresponding to a modulator (48), and transmit data registers (TXDATA[5]-TXDATA[0]) sequentially receiving the digital data values from the GSM unit.

Abstract: A device for generating a radio frequency electrical signals, delivering at least two separate signals having different frequencies, in the form of signals delivered by different primary sources and amplified with a predetermined gain. The device comprises a combining circuit (3), combining the signals delivered by the primary sources (2), a single channel power amplifier (4) and a multi-channel selection and routing unit (5) with a parallel structure. Each channel delivers at the output an amplified signal (S) at a frequency (F) characteristic of one of the primary sources (2) and comprises a filter circuit (6) adjusted to be passing for one of the different characteristic frequencies (F) of the different primary sources (2), an impedance adaptation circuit (7) and a rejection circuit (8) for frequencies other than the passing frequency of the filter circuit (6) of the channel in question.

Abstract: An input signal of varying amplitude and varying phase is converted into more than two signals of constant amplitude and controlled phase. Each of the more than two signals of constant amplitude and controlled phase is then separately amplified in separate amplifiers. The separately amplified more than two signals of constant amplitude and controlled phase are then combined to produce an output signal that is an amplification of the input signal at the desired power level. When converting the input signal into more than two signals, the phase of each of the more than two signals of constant amplitude and controlled phase is controlled to produce the output signal that is an amplification of the input signal at the desired power level. According to another aspect, a signal of varying amplitude and varying phase is generated from a plurality of constant amplitude varying phase signals, the sum of which is the signal of varying amplitude and varying phase.

Abstract: The invention relates to a transmitter and a method of generating a transmission signal. A first modulation device 12 generates an uncompensated transmission signal Y(t) by modulating at least one baseband signal I, Q with a respective oscillation signal LOQ, LOI. It is an object of the invention to improve a transmitter with such a modulation device so as to reduce the expenditure for the filtering at a later stage that is necessary to attenuate undesirable components in the uncompensated transmission signal Y(t). This object is achieved according to the invention in that a compensation signal C(t) is formed on the output of a second modulation device (14), said compensation signal representing essentially the components to be compensated in the uncompensated transmission signal Y(t). The compensation signal is generated in the second modulation device by modulation of the baseband signals I, Q with suitable auxiliary oscillation signals.

Abstract: The present invention provides a method for controlling a communication parameter in a channel through which data is transmitted between a transmit unit with M transmit antennas and a receive unit with N receive antennas by selecting from among proposed mapping schemes an applied mapping scheme according to which the data is converted into symbols and assigned to transmit signals TSp, p=1 . . . M, which are transmitted from the M transmit antennas. The selection of the mapping scheme is based on a metric; in one embodiment the metric is a minimum Euclidean distance dmin,rx of the symbols when received, in another embodiment the metric is a probability of error P(e) in the symbol when received. The method can be employed in communication systems using multi-antenna transmit and receive units of various types including wireless systems, e.g., cellular communication systems, using multiple access techniques such as TDMA, FDMA, CDMA and OFDMA.