Abstract: A multiphase clock generation circuit (111) for generating a multiphase clock signal, a phase subdivision unit (113) for shifting a phase of the multiphase clock signal output from the multiphase clock generation circuit (111), and a clock selection unit (114) for selecting one of clock signals output from the phase subdivision unit (113) are provided. A PLL circuit (120) for receiving an output from a frequency division circuit (115) is further provided. The phase shift carried out by the phase subdivision unit (113) and the selection of the clock signal carried out by the clock selection unit (114) are controlled by a frequency control unit (112) to switch SSC ON/OFF and to change the bandwidth of the PLL circuit (120).

Abstract: A tire pressure monitoring system is capable of ensuring accuracy of the rate of transmission of data via wireless communications without an increase in the number of oscillators and an increase in the cost. The tire pressure monitoring system includes a tire pressure measuring module. The tire pressure measuring module has a microcomputer, an activation control circuit, a pressure sensor, a temperature sensor, a frequency divider, a transmitting circuit, and a battery. The microcomputer has a clock pulse generator, analog-to-digital converter circuits and a controller. The transmitting circuit has an oscillator circuit. The frequency divider divides the frequency of a carrier wave CW output from the oscillator circuit to generate a clock signal, and outputs the clock signal to the controller included in the microcomputer. The clock signal is used for the timing for outputting data to a data signal line DL.

Abstract: Additional data may be added to the current SDARS satellite signals as a phase and/or amplitude offset from the legacy quadrature phase shift keying (QPSK) modulated data and transmitted by the SDAR terrestrial repeaters. However, in the case where a legacy receiver architecture for a differential modulation system outputs angular/phase differences between carriers, the phase and/or amplitude information appears as distortion to the legacy receiver. The present invention provides a method for optimizing the SDARS infrastructure more efficiently by allowing independent adjustment of the phase and/or amplitude offset (610) at each terrestrial site. The present invention provides a method for adjusting the performance of each signal together or separately as needed.

Abstract: A wireless communication method, a radio transmitter apparatus and a radio receiver apparatus wherein a signal sequence, which is used in a reception process using a first modulation scheme and can be generated from a signal sequence prepared for a reception process and used in a second modulation scheme, is employed, thereby achieving a performance to a similar extent to the reception process performance using the second modulation scheme. A radio transmitter apparatus (20) uses a first modulation scheme (e.g., OOK modulation scheme) to sequentially transmit, as a first sequence, both a sub-sequence a1(n), which is identical with a second sequence a(n) designed for use in a second modulation scheme (e.g., BPSK modulation scheme), and a sub-sequence a2(n), the bits of which are reverse to those of the second sequence a(n), in a time division manner.

Abstract: An apparatus for independently extracting streams from a hierarchically-modulated signal and performing a soft-decision, and a method thereof are provided. The apparatus includes: a synchronizing unit for receiving a hierarchically-modulated signal configured of an I-channel signal and a Q-channel signal from an external device and performing a synchronizing process on the received signal; a divaricating unit 410 for divaricating the synchronized signal configured of the I-channel signal and the Q-channel signal from the synchronizing unit; a high priority (HP) stream extracting and soft-decision unit for extracting a HP stream from one of the divaricated signals, and performing a soft-decision; a processing unit for processing the other of the divaricated signals to allow constellation points to be distinguished; and a low priority (LP) stream extracting and soft-decision unit for extracting a LP stream from the processed signal from the processing unit and performing a soft-decision.

Abstract: An apparatus and method for generating piecewise linear phase transitions during a phase transition interval of a first signal to control controlling the phase/frequency of a second signal. The initiation point, duration and shaping parameters of the piecewise linear phase transitions are selected to control adjacent channel emissions in the second signal.

Abstract: The invention relates to methods and circuits for compensating linear in-band distortions such as those occurring in RF circuits of broad band communication systems. A low-rate sampling is used to collect statistical information about a modulated signal after it passed through the distorting circuits, which is then compared to reference statistical information for the modulated signal to iteratively adjust a frequency response of an equalizing linear filter inserted into the signal path so as to compensate for the distortions.

Abstract: A system for encoding data in a multilane communication channel may include at least one processor operable to generate, from existing control characters in a character set, expanded control characters utilized for controlling the data in each lane of the multilane communication channel. Each lane of the multilane communication channel may transport the data in a similar direction. The at least one processor is also operable to control at least one of the lanes of the multilane communication channel using at least one of the generated control characters. If a first control character of the existing control characters is a start-of-packet control character, the at least one processor is then operable to select a second control character from any other of the generated expanded control characters, and to indicate a start of a packet using the selected second control character for at least one of the lanes.

Abstract: Methods for determining an inter-slot power level are disclosed. In one example embodiment, the inter-slot is positioned between first and second timeslots capable of transmitting modulated signals. A first timeslot power level and a second timeslot power level are first acquired. A power level of the inter-slot is then determined using the first and second timeslot power-levels. In this example embodiment, the inter-slot power level is maintained within a predetermined deviation from a specific range. The specific range is defined by the first and second timeslot power-levels.

Abstract: A method for generating a preamble of an Orthogonal Frequency Division Multiplexed (OFDM) data frame for a multiple input multiple output (MIMO) wireless communication includes determining at least one system condition preamble format parameter. When the system condition preamble format parameter satisfies a first preamble format parameter a preamble having a first preamble format is formed. When the system condition preamble format parameter satisfies a second preamble format parameter, a preamble having a second preamble format is formed. Further, when the system condition preamble format parameter satisfies a third preamble format parameter, a preamble having a third preamble format is formed. The first, second, and third preamble formats differ based upon their lengths, fields, and modulation formats of a high throughput signal field.

Abstract: The present invention proposes a channel encoder, and a channel encoding method executed by the channel encoder comprising the steps of: (a), converting the serial data stream to be encoded into multiple parallel signals; (b). interleaving the multiple parallel signals; (c). according to predefined encoding rule, encoding the multiple parallel signals and interleaved multiple parallel signals separately to obtain encoded multiple parallel signals; and (d). transmitting the interleaved multiple parallel signals and the multiple parallel signals via multiple Tx antenna cyclically and alternately. The channel encoder according to the present invention can achieve better decoding performance at receiver due to the combination of Turbo encoding scheme.

Abstract: A system and method for performing baseband phase shifting in a Cartesian feedback system includes a forward path for receiving an input baseband signal having two components, and performing up-conversion to output a RF signal; a power amplifier for amplifying the RF signal output from the forward path; and a feedback path for down-converting at least a sample of the output from the power amplifier to a feedback baseband signal comprising two components, and providing the feedback baseband signal to the forward path in order to be summed with the input baseband signal at a summing junction and before the loop filter. The forward path includes a baseband phase shifter for adjusting the baseband signal output from the summing junction in order to compensate for any phase shifts induced in the system.

Abstract: A system and method for arbitrarily switching phase and amplitude at an antenna. A Direct Spatial Antenna Modulation (DSAM) system makes use of the spatial characteristics of a radiating antenna structure to directly alter a signal transmitted or received by the radiating structure. A data stream maps a carrier to different spatial points of excitation in the antenna structure, where each chosen configuration has different radiating characteristics including phase, amplitude, and polarization, which can be used represent data symbols. The spatial points of a radiating structure may be mapped directly to In-Phase and Quadrature components of the output using two spatial feedpoints and amplitude control to the feedpoints. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this Abstract.

Abstract: A modulator including a direct modulation synthesizer circuit, a reference frequency oscillator for providing an input reference signal to the direct modulation synthesizer circuit for locking a carrier frequency to a stable frequency and a pre-emphasis unit for data bits and for producing a modulating signal for direct modulation of the direct modulation synthesizer circuit, the modulating signal having data bit dependent voltage levels.

Abstract: A ZigBee communication apparatus and method for high-speed transmission and reception are provided. The apparatus includes a controller, a first transmission unit, and a second transmission unit. The controller outputs a first control signal controlling high-speed transmission and a second control signal controlling general transmission. The first transmission unit transmits data at high speed when receiving the first control signal. The second transmission unit transmits data at general speed when receiving the second control signal.

Abstract: Embodiments of a circuit are described. In this circuit, a modulation circuit provides a first modulated electrical signal and a second modulated electrical signal, where a given modulated electrical signal, which can be either the first modulated electrical signal or the second modulated electrical signal, includes minimum-shift keying (MSK) modulated data. Moreover, a first phase-adjustment element, which is coupled to the modulation circuit, sets a relative phase between the first modulated electrical signal and the second modulated electrical signal based on a phase value of the first phase-adjustment element. Additionally, an output interface, which is coupled to the first phase-adjustment element, is coupled to one or more antenna elements which output signals. These signals include a quadrature phase-shift-keying (QPSK) signal corresponding to the first modulated electrical signal and the second modulated electrical signal.

Abstract: A radio frequency modulating circuit of a transmitter includes a phase multiplexer including a plurality of phase followers each coupled to a selector and operating in accordance with a corresponding pair of complementary-level carrier signals received thereby. The selector is operable to enable conduction of one of the phase followers therethrough in response to a data sequence modulated from a data stream by a phase shift keying modulating circuit. A conversion amplifier is operable in accordance with the complementary-level carrier signals of a conducting one of the phase followers so as to output a phase-modulated output corresponding to the data stream. The phase-modulated output is amplified by a power amplifier and is transmitted through an antenna.

Abstract: A power amplifier (106) has a linear operation mode for performing power amplification by use of a linear operating domain in an input-output power characteristic and a saturation operation mode for performing power amplification by use of a saturation operation domain in the input-output power characteristic. An amplitude control section (112) outputs gain control voltage data for controlling a gain of a gain control amplifier (105) and power control voltage data for controlling a source voltage of a power amplifier (106) in accordance with a transmission power setting value, thereby causing the power amplifier (106) to operate in any one of the operation modes.

Abstract: Provided is a radio communication base station device capable of acquiring both a multi-user diversity effect and a frequency diversity effect simultaneously in multi-carrier communications. In this device, modulation units (101-1 to 101-n) modulate data to mobile stations (MS#1 to MS#n) individually to create data symbols. A separation unit (102) separates each data symbol inputted, into an Ich (in-phase components) and a Qch (orthogonal components). An Ich arrangement unit (103) and a Qch arrangement unit (104) arrange the Ich and Qch, respectively, in a plurality of sub-carriers constituting an OFDM symbols, and output the same to a synthesization unit (105). This synthesization unit (105) synthesizes the Ich and Qch arranged for each sub-carrier, to create the synthesized symbol.

Abstract: The present invention provides a method, receiver and transmitter for use in a SDAR system. The method involves generating a first modulated signal based on first input data. Additional modulation is superimposed on the first modulated signal based on additional input data, being spread across a plurality of symbols in the first modulated signal in a predetermined pattern to generate a modified signal which is then transmitted. The modified signal is decoded by performing a first demodulation of the first modulated signal then additional demodulation is performed to obtain additional input data. The superimposing step uses a plurality of offset sequence values to add the additional modulation to the first modulated signal. The offset sequence may appear as a pseudo-random distribution of offset sequence values, and may include at least one zero offset value.

Abstract: Compensating for wideband quadrature imbalance error by introducing inverse complex inputs to phase quadrature estimator filters to generate estimated quadrature distortion; summing estimator quadrature distortion with a delayed version of the actual complex input to obtain estimated quadrature output; comparing the output with the true output to obtain residual quadrature imbalance error; applying a least mean square to the inverse input and imbalance residual error to obtain an updated estimate of filter coefficients; updating the filter coefficients of the phase quadrature estimator; and updating the filter coefficients of a phase quadrature compensator with the filter coefficients of the phase quadrature estimator to obtain a quadrature output pre-compensated for quadrature imbalance error.

Abstract: A method for transmitting a base band digital data signal having a bit period and a first bandwidth, comprising providing a carrier wave having a carrier amplitude and a carrier frequency, and synchronously modulating both the carrier amplitude and carrier frequency with the base band digital signal, so as to reduce the bandwidth of the modulated carrier wave below the bandwidth of the base band signal. A method for transmitting a base band digital data signal having a bit period and a first bandwidth, comprising providing a carrier wave having a carrier phase and a carrier frequency, and synchronously modulating both the carrier phase and carrier frequency with the base band digital signal, so as to reduce the bandwidth of the modulated carrier wave below the bandwidth of the base band signal.

Abstract: A wireless communication system may include a first wireless communications device, and a second wireless communications device. The first wireless communications device may include a wireless transmitter, and a modulator coupled to the wireless transmitter for modulating input data to generate a Gaussian phase shift keyed signal having a selected data symbol mapping. The second wireless communications device may include a wireless receiver, and a demodulator coupled to the wireless receiver for demodulating the Gaussian phase shift keyed signal using memory-less symbol decisions based upon the selected data symbol mapping.

Abstract: An example method includes modulating an optical signal using a Phase Shift Keying (PSK) signal constellation, wherein signal points of the PSK signal constellation are located on at least two rings. The first ring has a first radius r1 and a second ring has a second radius r2, wherein the first radius and second radius differ, and wherein the signal points are not located on a regular n-dimension lattice, where n is an integer. The regular n-dimension lattice is formed from a minimum number of lines parallel to an axis for each of the n-dimensions that connect ones of the signal points of the PSK signal constellation on either side of an origin of the axis. The second radius may be greater than the first radius, with the second radius a non-integer multiple of the first ring radius.

Abstract: A method and system of data transmission; the method comprising: converting data into qubits; transmitting a first qubit; measuring the first qubit at receiver location; determining whether or not to transmit portions of data from a sequential successive qubit based upon the value of the first qubit measured at the receiver location.

Abstract: A simple, interference-free digital phase modulator is to be provided. To this end, the phase modulator is provided with a counter for outputting a counter signal on the basis of a predetermined clock signal and a comparator, which receives a current counter state from the counter, in order to record a digital input signal. The comparator compares the input signal with the current counter state on the basis of a predetermined allocation table and resets the counter, if the input signal corresponds to a counter state assigned via the allocation table. A predetermined signal value of the output counter signal is herewith phase-modulated as a function of the input signal. As only one phase position is generated with the circuit at any point in time, interferences, which are produced by the digital phase modulator itself, are significantly less.

Abstract: Improvements to a layered modulation (LM) implementation are disclosed. The present invention discloses two implementations of LM, using single and multiple transponders per signal frequency, respectively. Layered hierarchical 8PSK (H-8PSK) is a special case of LM. By re-encoding the high-priority (HP) portion of an H-8PSK signal, LM can improve carrier-to-noise ratio (CNR) of a H-8PSK signal. LM can be computer-simulated and a two-layered signal can be sequentially demodulated with a predicted CNR performance. An LM signal can be simulated using live signals for off-line processing. In addition, a signal processing apparatus can process in real time LM signals emulated from live satellite signals.

Abstract: A radio communication apparatus capable of switching modulation schemes includes a QPSK modulation signal generator configured to modulate transmission data by a QPSK modulation scheme and to output a QPSK modulation signal. A 64QAM modulation signal generator is configured to modulate transmission data by a 64QAM scheme and to output a 64QAM modulation signal. A radio processor is configured to receive, as an input, the QPSK modulation signal or the 64 QAM modulation signal and to output a transmission signal. A transmission power amplifier is configured to amplify a power of the transmission signal. The QPSK modulation signal generator and the 64QAM modulation signal generator perform gain control so as to make an average transmission power of the 64QAM modulation signal smaller than an average transmission power of the QPSK modulation signal.

Abstract: A circuit for transmission and reception of multi-channel communications is disclosed. The transmitter path includes a digital modulation circuit receiving multiple channel binary data, and for each channel generating a digital representation of the data. A digital-to-analogue (D/A) conversion circuit (140-146) is provided for each data channel. Each D/A conversion circuit receives and converts respective channel digital representations to produce a resultant band limited analogue signal (148-154). The band limitation arises due to a characteristic of said channel digital representations. A bandpass filter (156-162) receives and filters each analogue channel signal. The band width to the start of the stop band of each bandpass filter is wider than a respective band limited analogue channel signal and wider than the Nyquist bandwidth arising from the sampling rate of said D/A conversion circuit. In this way, signal power in unwanted Nyquist zones is effectively removed.

Abstract: A method and apparatus of transmitting control information in a wireless communication system is provided. A sequence corresponding to control information from a sequence set is determined. A reference modulation symbol set corresponding to a mini unit by modulating the sequence is generated. At least one reordered modulation symbol set is generated by reordering and repeating the reference modulation symbol set. The at least one reordered modulation symbol set is reordered in a unit of a subgroup. The reference modulation symbol set and the at least one reordered modulation symbol set are mapped to the plurality of mini units in the resource unit respectively.

Abstract: A quadrature modulation circuit includes a mixer circuit including an integrated sign modulation control circuit and a plurality of mixer ports. The mixer ports include a first input port, a second input port, an output port and a sign modulation control port. The modulation circuit generates a modulated signal by operation of the mixer circuit multiplying a modulating signal applied to the first input port with a carrier signal applied to the second input port to generate a mixed signal output from the output port, and by operation of the integrated sign modulation control circuit controlling polarity switching of a signal at one of the mixer ports in response to a sign modulation control signal input to the sign modulation control port.

Abstract: A method for implementing phase rotator circuits and phase rotator circuit of the invention includes a polyphase filter network to create a quadrature phase version of the input signal. The polyphase filter network is partitioned into a first part that is physically isolated from the phase rotator circuit and a second part that is embedded in the phase rotator circuit. The second part of the polyphase filter is coupled to the first part of the polyphase filter by a high-pass equalizing buffer stage. The second part of the polyphase filter is coupled to the phase rotator circuit by a bandlimiting buffer stage.

Abstract: A method of optically equalizing a multi-level (amplitude or phase) optical signal through the effect of an optical equalizer wherein the optical equalizer (OEQ) is placed at either a transmission end or a receiver end of the optical communications link and a tap delay characteristic of the OEQ need not be determined by symbol spacing, rather it may advantageously be adjusted to desirably compensate non-linear mapping performed in the modulation process or simultaneous operation on a plurality of wavelength division multiplexed (WDM) channels.

Abstract: A system for and method of converting successive bits of digital data into BPSK symbols using one or more BPSK symbol constellations such that orthogonal BPSK constellations are referenced to successive bits of the digital data. The system and method may toggle between referencing first and second orthogonal constellations as successive bits of the digital data are encountered. Alternatively, the system and method may successively rotate by 90° the constellation to be referenced as successive bits of the digital data are encountered. The reversal of the systems and methods described can be used to decode a transmission made by the methods described or specifically to reference a succession of orthogonal BPSK constellations to convert a succession of BPSK symbols to a succession of bits of digital data. Furthermore, a standard quadrature receiver can be used to perform the conversion.

Abstract: A modulator for radio-frequency signals designed an entirely digital modulator has two mixer stages connected in series. The first mixer stage implements with a relatively low first sample rate a frequency mixing with a first oscillator frequency that is adjustable with high precision. The second mixer stage implements a frequency mixing with a significantly higher second sample rate and with a relatively coarsely adjustable second oscillator frequency. The downstream second mixer stage, in the case of a single mixer stage, the mixer stage, has at least two phase accumulators that are incremented with the higher second sample rate but with different incremental values. The output signal of at maximum one of the phase accumulators is evaluated at any point in time.

Abstract: A base station for use in a wireless network that communicates with wireless mobile stations. The base station comprises: 1) a transceiver for transmitting forward channel data to a first mobile station via a beam-forming antenna array; and 2) a beam-forming circuit for maximizing data throughput to the first mobile station by jointly optimizing i) selection of a beam for transmitting the forward channel data to the first mobile station, ii) a level of Walsh code multiplexing of the forward channel data, and iii) a modulation scheme used to transmit the forward channel data.

Abstract: Modulator system (1) comprising modulators (2, 3, 4) for modulating input signals (A) according to different modulation schemes (8PSK, GMSK) cause discontinuities in the output signals (F) when switching between the schemes. By providing the modulator systems (1) with compensators (13, 22-26) for compensating amplitudes/phases of the output signals (F) of the modulator system (1) for discontinuities, these discontinuities resulting from modulation scheme changes are reduced to a large extent. This may be done before/after the pulse shapers (11, 21). The compensators (13, 22-26) comprise multipliers for multiplying pulse shaped modulated signals with complex valued waveforms (E), or for multiplying modulated signals with waveforms (S, T), or for multiplying complex valued signals (B, C, D) with complex valued phase offsets (X, Y, Z), which complex valued signals (B, C, D) are to be multiplied with mapped input signals.

Abstract: A disclosed precoder circuit is used for differential phase shift keying and includes multiple levels of parallel precoder units, each of which is configured to perform a precoding operation using a data signal having multiple symbols and one of a fixed value and a one-symbol preceding modulated signal output from a preceding-level parallel precoder unit so as to obtain a modulated signal, precoding operations of the parallel precoder units being simultaneously performed in a parallel fashion; multiple levels of re-timing units configured to synchronize modulated signals output from the parallel precoder units; and multiple levels of offset units, each of which is configured to add a phase difference between the fixed value and the one-symbol preceding modulated signal to the modulated signals output from the corresponding re-timing units.

Abstract: A wireless communication device, a wireless communication system and a method for transmitting a packet preamble of signal sequences to both a single carrier wireless device and a multiple carrier wireless device. The packet preamble includes a first sequence for detecting a signal and a second sequence for estimating a channel.

Abstract: Provided is a wireless communication apparatus wherein channel estimation accuracy is improved while keeping the position of each bit in a frame, even when a modulation system having a large modulation multiple value is used for a data symbol. In the wireless communication apparatus (100), an encoding section (101) encodes and outputs transmitting data (bit string) to a bit converting section (102), and the bit converting section (102) converts at least one bit of a plurality of bits constituting a data symbol to be used for channel estimation, among the encoded bit strings, into ‘1’ or ‘0’ and outputs it to a modulating section (103). The modulating section (103) modulates the bit string inputted from the bit converting section (102) by using a single modulation mapper and a plurality of data symbols are generated.

Abstract: In a multivalue modulation type with one pilot symbol inserted for every 3 or more symbols, signal points of each one symbol immediately before and after a pilot symbol are modulated using a modulation type different from that for pilot symbols. In this way, it is possible to suppress deterioration of the accuracy in estimating the reference phase and amount of frequency offset by pilot symbols and improve the bit error rate characteristic in the signal to noise ratio in quasi-coherent detection with symbols whose symbol synchronization is not completely established.

Abstract: A circuit 30 for upsampling and upconverting a high rate signal that is divided into M in-phase (I) symbols and M quadrature (Q) symbols. A Nyquist filter 32 upsamples by a factor of k each of the 2M symbols in parallel during one system clock period (CP). The filter 32 has a plurality of 2kM filter components 40, 42, that each provides a continuous output. A plurality of multipliers 50, 52 each upconverts a filter component output with a carrier wave signal 46, 48 that is output from a numerically controlled oscillator 44. A plurality of adders 54 each adds the output of two multipliers 50 to recombine corresponding I and Q samples to output kM samples during a CP. For continuous phase modulation, N parallel bits are input into the filter 32, upsampled in one CP, and accumulated and modulated 82 in parallel in one CP. For analog processing, M (I) and M (Q) symbols are input into an FIR filter 77a, 77b for upsampling, and decimated at a MUX/DAC block 78 for subsequent analog upconversion.

Abstract: At a base station apparatus, known pilot signals for use in channel estimation are transmitted, and in addition thereto MCS pilot signals that are used to perform adaptive modulations respectively corresponding to a plurality of modulation schemes are multiplexed and output. A mobile station apparatus dispreads the respective MCS signals out of the multiplex signal, compares these to known symbols patterns, and sends the MCS pilot signals that show a matching relationship to the base station apparatus as a mobile station reception result. Upon receiving the mobile station reception result from the mobile station apparatus, the base station apparatus selects the modulation scheme of the optimum modulation level for the downlink signals. This configuration makes it possible to switch the modulation schemes in an accurate and simple way.

Abstract: An apparatus comprising a first circuit, a second circuit, a third circuit and a fourth circuit. The first circuit may be configured to generate a demodulated signal in response to (i) a modulated signal and (ii) a seed value. The second circuit may be configured to generate a first control signal in response to the demodulated signal. The third circuit may be configured to generate a second control signal in response to (i) the first control signal and (ii) a compensation signal. The fourth circuit may be configured to generate the seed value in response to the second control signal.

Abstract: Disclosed are a radio communication terminal device, a radio communication base station device, and a radio communication method which can prevent input of an interference wave peak into a detection window of a cyclic shift sequence allocated to a local cell and improve the channel estimation accuracy in a base station. A frequency serving as a reference is set for a transmission band width of all the cells and respective terminals in which frame synchronization is established. By using the frequency as a reference point, a phase rotation addition unit (110) of a reference signal generation unit (108) adds a phase rotation corresponding to a frequency difference ?; between the transmission band of the reference point and that of the reference signal to a ZC sequence as a reference signal in the frequency region. The ZC sequence to which the phase rotation is added is multiplexed with transmission data in a multiplexing unit (114) and a multiplexed signal is transmitted from a transmission RF unit (115).

Abstract: A concatenated coding scheme, using an outer coder, interleaver, and the inner coder inherent in an FQPSK signal to form a coded FQPSK signal. The inner coder is modified to enable interative decoding of the outer code.

Abstract: A transmitter providing a wide output control variable width with high efficiency is provided. Saturation mode operation is performed in the vicinity of the maximum transmission power and the input level of a large power amplifier is enlarged and fixed. When the large power amplifier is operated in a saturation state, the amplitude component of a modulation signal is input to an R input terminal in the range responsive to an output power control level and power supply voltage of a power supply terminal is amplitude-modulated, whereby highly efficient polar coordinate modulation is performed. In smaller transmission power, linear mode operation is performed, the input level of the large power amplifier is lessened for operating the large power amplifier in the linear mode, and the power supply voltage of the power supply terminal is made variable in response to the output power control level, whereby transmission power control is performed.

Abstract: The present disclosure relates to circuits and methods for improving the performance of a polar modulator by maintaining the input to a phase modulator.

Abstract: The present invention relates to a digital I/Q modulator which efficiently supports multi-time-slot operation of wireless TDMA transmitters employing linear power amplifiers. According to the present invention, dips are introduced in the envelope of the I/Q signal in the guard interval between adjacent time-slots or bursts. The dips avoid interference on adjacent radio frequency channels when the gain of the TX chain in switched abruptly in order to change the power level of the TX signal or when the modulation scheme is changed. Also, a method is provided for generating the dips, which is particularly attractive if the modulation scheme in adjacent time-slots changes from GMSK to 8PSK or vice versa.

Abstract: A method and system generates a higher order modulation, in which a complex sequence of binary digits corresponding to symbols of a higher order modulation is received. The symbols correspond to constellation points of the higher order modulation. First mapping means map the symbols of the higher order modulation to first constellation points of a first QPSK modulation and output an output signal of the first QPSK modulation corresponding to the first constellation points. Similarly, second mapping means map the symbols of the higher order modulation to second constellation points of a second QPSK modulation and output an output signal of the second QPSK modulation corresponding to the second constellation points. Adding means add the output signals of the first and second QPSK modulations, thereby generating the constellation points of the higher order modulation.