Abstract: A mixer is connected to a signal generator and an antenna and outputs a signal at an intermediate frequency. A PLL demodulator subjects the signal at the intermediate frequency from the mixer to PLL demodulation. An amplifier amplifies a signal from the PLL demodulator. A detector detects an amount of shift occurring in the PLL demodulator. A detector detects a gain of the amplifier. An FSK demodulator subjects a signal from the amplifier to FSK demodulation. An AFC unit detects a frequency offset in the signal from the amplifier and causes the signal generator to make a correction for the frequency offset detected.

Abstract: A computing system includes: an inter-device interface configured to receive communication signal for communicating between a device and a further device; a communication circuit, coupled to the inter-device interface, configured to: calculate an initial offset estimate based on the communication signal, dynamically generate a dynamic candidate set based on the initial offset estimate, and determine a level offset for the communication signal for communicating between the device and the further device.

Abstract: A receiving apparatus receives an FSK signal, converts the FSK signal into a phasor including amplitude and phase, estimates and compensates for a CFO (carrier frequency offset) from the converted phasor, and recovers a data bit from the converted phasor.

Abstract: A circuit and a method for removing a frequency offset and a communication apparatus including the circuit, capable of removing the frequency offset by tracking rapidly and accurately in a payload section. A sequence of sample levels is obtained by sampling a frequency level of the baseband signal at every 0.5 symbol interval. Absolute values of differences between the frequency levels adjacent to each other at every 1 symbol are calculated as first difference absolute values. Absolute values of differences between the frequency levels adjacent to each other at every 1 symbol are calculated as second difference absolute values. When the first difference absolute values are greater than a predetermined first determination value or the second difference absolute values are less than a predetermined second determination value, the average value calculated is set as the frequency offset.

Abstract: A plurality of audio signals are broadcasted concurrently on a plurality of substantially separate audio channels. Each of the audio channels has a center frequency greater than approximately 16 kHz. Broadcasting the audio signals causes one or more clients to automatically retrieve a resource from a resource location. The plurality of audio signals collectively encode a resource identifier that describes the resource location.

Abstract: The receiver (1) picks up low rate FSK radio frequency signals. This receiver includes an antenna (2) for receiving FSK radio frequency signals, a low noise amplifier (3) connected to the antenna, a local oscillator (7) for supplying oscillating signals (LO), a phase shift circuit (16) for performing a 0° to 90° phase shift, and vice versa, in the oscillating signals (LO) or the incoming FSK radio frequency signals in each semi-period of a phase switching cycle (1/fs). The phase shift circuit alternately and successively generates in-phase and quadrature oscillating signals, or in-phase and quadrature incoming FSK radio frequency signals. The receiver includes a single mixer (4) for mixing the oscillating signals successively with the incoming FSK radio frequency signals, so as to generate alternately intermediate in-phase and quadrature baseband signals (INT) as a function of the phase shift circuit.

Abstract: The high sensitivity FSK radiofrequency signal receiver includes an antenna for receiving FSK radiofrequency signals, a LNA amplifier receiving signals picked up by the antenna, a local oscillator for supplying oscillating signals, a mixer for mixing the incoming signals with the oscillating signals to produce intermediate signals. The receiver includes a broadband or poly-phase filter for filtering the intermediate signals, and a sampler for supplying sampled intermediate signals to a high sensitivity demodulation stage, which supplies data signals. The receiver includes a processing circuit for performing a discrete Fourier transform of sampled intermediate signals. The selector at the processing circuit output determines the difference between the signal amplitude peak frequency above a determined threshold and the expected frequency of the intermediate signals.

Abstract: A method and apparatus for decoding binary frequency shift key signals in which an exclusive-OR of the sign of a real waveform with a sign of the imaginary waveform at a time shortly after the real (or, alternatively, the imaginary) waveform crosses zero is used to determine a bit represented by the signal. In some embodiments, particularly those in which the bit period is about one-half of the carrier signal frequency, both the real and imaginary waveforms are monitored to detect the zero crossing in order to account for the situation in which data transitions prevent zero-crossings on one of the waveforms.

Abstract: A mobile electronic device that includes a circuitry configured to acquire synchronization with a spreading code of an intermediate frequency signal that is obtained by converting a frequency of a received signal from a satellite in a global positioning system into a predetermined intermediate frequency, demodulate a message included in the intermediate frequency signal, output a primary signal to a predetermined signal line, and attach a predetermined header to a secondary signal and output the result to the predetermined signal line, and includes a display unit configured to display data corresponding to the primary signal and the secondary signal, such that the primary signal includes results of measuring one of position, velocity, and time of the mobile electronic device based on the message that is demodulated by the circuitry, and that the secondary signal includes the intermediate frequency signal.

Abstract: Examples of systems and methods are provided for converting an analog input signal to a digital output signal. A system may include a current mode (CM) digital-to-analog converter (DAC) circuit to provide a DAC current. A comparator circuit may be configured to generate a comparator signal in response to an error signal determined based on the DAC current and the analog input signal. A successive approximation register circuit may be configured to generate at least one of a DAC-code signal or the digital output signal, in response to the comparator signal. The DAC-code signal may be used by the CM DAC circuit to control the DAC current.

Abstract: Improvements are disclosed for in-band signaling, i.e., transmission of data in a voice channel of a digital wireless network during a voice call session. A family of narrow-band signaling methods, some employing tapered waveforms, is disclosed to successfully pass data-carrying signals through the low-bit rate modes of the EVRC-B vocoder commonly used in CDMA wireless channels. These features can be used in cell phones or other wireless communication devices, including automotive applications.

Abstract: An apparatus includes Radio Frequency (RF) circuitry, multiple message sources and strobe multiplexing logic. The RF circuitry is configured to synchronize communication of RF signals based on reception of strobe messages. The multiple message sources are each configured to generate respective ones of the strobe messages for synchronizing the RF circuitry. The strobe multiplexing logic is configured to multiplex the strobe messages originating from the multiple message sources, and to send the multiplexed strobe messages over a single digital interface to the RF circuitry.

Abstract: A method and device for multi-user detecting of an OFDM transmission signal are provided. The method includes: combining received signals, at corresponding time-frequency symbol positions in all of multiple repeated Block Units in relation to the same data symbol, into a received data sequence; determining a combined repeated channel response sequence array corresponding to the received data sequence; and detecting the received data sequence using the combined repeated channel response sequence array to obtain data symbols of multiple users. The technical solution can effectively restrain the multi-address interference and the interference between symbols during OFDM transmitting signal and improve the system performance greatly.

Abstract: In a radio communication system in which multiple bands or a plurality of different radio frequencies are used, a different radio transmission method is used in each band or at each radio frequency. For example, by transmitting data using radio formats which are different in each band or at each radio frequency, the radio transmission method is made different in each band or at each radio frequency. In order to vary the radio format, (1) the pilot length is varied at each radio frequency; or (2) the pilot interval is varied at each radio frequency; or (3) the guard interval length is varied in each band or at each radio frequency; or (4) when multicarrier modulation is used for radio communication in each band, the subcarrier interval for multicarrier transmission is varied in each band.

Abstract: The invention discloses a transmitting apparatus. The transmitting apparatus uses the same transmission medium to transmit two signals that are within different frequency ranges at the same time. The transmitting apparatus increases the transmitting paths of the transmission medium so as to enhance the use of the transmission medium and save the production costs.

Abstract: Embodiments of the present invention provide a hybrid analog to digital converter that may include a DAC coupled to a hybrid analog to digital converter input; an integrator having an input coupled to the hybrid analog to digital converter input and the DAC, and generating an integrator output; a comparator coupled to the integrator output and having a comparator output; a successive approximation register coupled to the comparator output; and a counter coupled to the comparator output to generate an hybrid analog to digital converter output. The hybrid analog to digital converter may be operable as a successive approximation register converter and a continuous time sigma delta converter.

Abstract: A CDMA receiving apparatus includes a path searcher which outputs path timing that corresponds to sample timing where a correlation value between a received data sequence and a reference code sequence reaches a peak, and outputs the correlation value calculated at a sample timing adjacent to the path timing as an adjacent timing correlation value; an interpolation adjuster; and a despreader which despreads an output of the interpolation adjuster at the path timing, wherein the interpolation adjuster includes an interpolator for generating an interpolating data sequence which is a data sequence displaced in time by a specified fraction of one sample period with respect to the received data sequence, and outputs the received data sequence or the interpolating data sequence by switching therebetween based on a result of a comparison between the correlation value calculated at the path timing and the adjacent timing correlation value.

Abstract: The present invention relates a system and method for mitigating impairment in a communication system. In one embodiment, the system comprises a transmitter adapted to transmit at least one signal and a receiver adapted to receive the at least one signal and mitigate inter code interference in the signal using at least one inter code interference coefficient.

Abstract: An integrated circuit device includes a sense amplifier with an input to receive a present signal representing a present bit. The sense amplifier is to produce a decision regarding a logic level of the present bit. The integrated circuit device also includes a circuit to precharge the input of the sense amplifier by applying to the input of the sense amplifier a portion of a previous signal representing a previous bit. The integrated circuit device further includes a latch, coupled to the sense amplifier, to output the logic level.

Abstract: An OFDM receiver apparatus receives an OFDM signal including a plurality of DBPSK signals transmitting identical information. An extraction unit extracts the plurality of DBPSK signals from the OFDM signal. A phase difference calculation unit calculates a phase difference between symbols of each of the plurality of extracted DBPSK signals. An accumulation unit accumulates the plurality of phase differences. A decision unit decides data transmitted by the DBPSK signals on the basis of an accumulation result.

Abstract: A method and apparatus for frame synchronization in digital communication systems using multiple modulation formats, including the Differential Phase Shift Keying (DPSK), Duobinary Signaling (DBS), and ON/OFF Keying (OOK) modulation formats, perform a search for both a frame alignment sequence (FAS) and the inverted FAS and determine the polarity of the received digital stream.

Abstract: A receiver arranged to receive a plurality of spread spectrum signals including a first spread spectrum signal from which interference caused by one or more others of said plurality of signals is to be removed, wherein at least one of said other spread spectrum signals has a spreading factor which is unknown to said receiver. The receiver comprises means for estimating a spreading factor of said at least one other spread spectrum signal having an unknown spreading factor, said estimating means selecting the spreading factor to be smallest possible spreading factor, means for despreading said at least one other spread spectrum signal using said estimated spreading factor, and means for estimating interference in the first spread spectrum signal caused by said at least one other spread spectrum signal.

Abstract: For demodulating radio navigation signals (s(t)) transmitted in spread spectrum and comprising a data channel modulated by a navigation message and a pilot channel not modulated by a navigation message, the data channel and the pilot channel are combined into one multiplexing scheme so as to modulate a carrier, this method consists in applying de-spreading processing to the pilot and data channels' signals and in demodulating the de-spread data signal (rd) in order to obtain the navigation message <d(t)>, the demodulation of the de-spread data signal (rd) used to obtain the navigation message <d(t)> is performed using the carrier (rp) obtained from the dispreading processing of the pilot channel.

Abstract: A microprocessor control unit (MCU) is mounted on a printed circuit board. The MCU includes first and second clocked serial interface (CSI) circuits. The first CSI circuit is configured to serially transmit a first xCP packet to a first encoder circuit, which in turn is configured to generate an encoded first xCP packet as a function of the first xCP packet and a first clock signal. A first low voltage differential signal (LVDS) circuit is coupled to the first encoder circuit and configured to serially receive the encoded first xCP packet therefrom. The first LVDS circuit is configured to generate a first differential signal as a function of the encoded first xCP packet.

Abstract: A method for using a wireless digital base station to receive, process and transmit a plurality of communications having independent data rates establishing a first communication channel having a first data communication rate to support a first communication; determining the data rate required to support the first communication; selecting one or more transmission channels, from a plurality of available transmission channels, required to support said required data rate; and transmitting the first communication using one or more selected transmission channels. The plurality of available transmission channels includes at least one B or D channel.

Abstract: A method for effectively allocating a transmission power and a method for transmitting SCH are disclosed. In this case, the transmission power of the SCH, which is important for initial cell search of the user equipment, is increased but is not allocated to a predetermined frequency region within one OFDM symbol to obtain the increased transmission power, thereby minimizing an influence on transmission of other channels within one OFDM symbol.

Abstract: A system and method for communicating a plurality of carrier waves that are received by a single receiver system is provided. The receiver system includes at least one antenna, at least one splitter, a plurality of tuners, and at least one combiner. The antenna receives a plurality of carrier waves. The splitter is in communication with the antenna, and splits the plurality of carrier waves. The plurality of tuners are in communication with the at least one splitter, and the split carrier waves are communicated to a separate tuner. The at least one combiner is in communication with the plurality of tuners, and combines an output of the plurality of tuners to generate an output based upon at least a portion of the received plurality of carrier waves.

Abstract: Improvements are disclosed for in-band signaling, i.e., transmission of data in a voice channel of a digital wireless network during a voice call session. A family of narrow-band signaling methods is disclosed to successfully pass data-carrying signals through the low-bit rate modes of the EVRC-B vocoder commonly used in CDMA wireless channels. Some embodiments generate a tapered signaling waveform in tandem with another waveform using FSK-modulation. These features can be used in cell phones or other wireless communication devices, including automotive applications.

Abstract: An apparatus and method for determining feedback information detection in a broadband wireless communication system are provided. In the detection determining apparatus, a demodulator correlates each of tiles carrying received feedback information with an orthogonal vector including a pilot symbol in each possible codeword, each tile being a predetermined number of subcarriers, and calculates the squares of the absolute values of the correlations. A codeword correlation calculator sums the squares of the absolute value of the correlations of the tiles for each possible codeword. A detection decider determines whether to perform detection on the feedback information based on the maximum of the sums.

Abstract: A method and a device for reducing the crest factor of a signal is operable to generate a correction signal as a combination of a plurality of partial correction signals having respectively predetermined frequencies and a signal having a reduced crest factor being issued as a differential between the correction signal and the signal. The respectively predetermined frequencies are selected such that the correction signal, which has a period length that is shorter than a length of the signal, is periodic. Therefore, according to the invention, only one period of the correction signal is determined and the correction signal is then determined as a periodic continuation of the one period.

Abstract: A method and an apparatus are provided, the apparatus includes a correlator configured to correlate samples of a frame format signal with a reference signal; an adder block configured to sum the correlation results over a given time period; a comparator configured to compare the sum with a given reference value; a controller configured, if the sum exceeds the reference value, to make the decision that a frequency correction channel has been detected, store the position of the frequency correction channel in the frame format signal and cease the correlation process; and otherwise configured to control the correlation and comparison to continue until the time reserved for the correlation process ends, to retain the value in the adder block; and to control the apparatus to resume the above process when a new time reserved for the correlation process is due.

Abstract: Disclosed are hybrid heterodyne transmitters and receivers for use in communications systems, or other systems, and the corresponding methods for hybrid heterodyne transmitting and receiving. A heterodyne receiver for converting a continuous time modulated signal to a discrete time digital baseband signal includes a sigma-delta modulator. The sigma-delta modulator is a sigma-delta analog-to-digital converter constructed and arranged to receive a modulated signal at an RF carrier frequency and provide a quantized output at a first intermediate frequency. The heterodyne receiver may also include a digital mixer constructed and arranged to receive a data stream quantized by the sigma-delta analog-to-digital converter and receive a signal at a second mixing frequency. The digital mixer then provides digital signals representative of a baseband signal suitable for digital signal processing.

Abstract: Multipath components of a signal transmitted through a time-varying digital radio channel are received with individual delays (?) within a range of possible delay values. An instantaneous delay profile indicating an instantaneous magnitude (g(?)) for each of a number of individual delays (?) is calculated repetitively, and an averaged delay profile indicating an averaged magnitude for the individual delays is generated from a number of repetitively calculated instantaneous delay profiles. The averaged delay profile is limited to comprise only delay values in a subset (W1, W2, W3) of the range of possible delay values. The delay of each individual multipath component is estimated from the averaged delay profile; and at least some estimated delays are used for RAKE combining. In this way, the benefits of an averaged delay profile are achieved without the need for the additional storage and computational resources normally required by a general averaged delay profile image.

Abstract: A multiphase receiver to compensate for intersymbol interference in the sampling of an input signal includes a first integrating receiver to integrate and sample data of the input signal on a first phase of a clock and a second integrating receiver to integrate and sample data of the input signal on a second phase of the clock. The multiphase receiver also includes an equalization circuit to adjust integration by the first integrating receiver dependent on a result of integration of data previously received by an integrating receiver distinct from the first integrating receiver, and to adjust integration by the second integrating receiver dependent on a result of integration of data previously received by an integrating receiver distinct from the second integrating receiver.

Abstract: A de-correlating discriminating system of code division multiple access signals including a system structure composed of a plurality of cells, each of the plurality of cells including a base-station and a plurality of user-stations, each of the user-stations including a user-transmitter and a user-receiver, communicating through a multi-access channel with the base station which includes a base-station receiver and a base-station transmitter, and the user-transmitter is capable of transmitting a data symbol to convey a data with a spreading sequence and a pilot symbol that is the spreading sequence to identify a channel from the user transmitter to the base-station receiver and the base-station receiver includes a minimum means square error detector to analyze an input vector that is a received signal containing both multiple users specific data responses.

Abstract: A device and method for effectively judging a communication quality in a communication system and a program used for the judgment. A communication device generates a four-value FSK symbol by adding a redundant bit to a bit of the most important part of encoded audio data. The symbol containing the redundant bit is set so that the symbol value is the maximum value of the minimum value of the four values which may be obtained. A reception device R receives the FSK modulation wave, restores the symbol, counts the number of redundant bits contained in the restored symbol and having incorrect values, decides whether to perform a bad frame masking process and what kind of bad frame masking process is to be performed, and executes the decided process. Thus, it is possible to accurately or rapidly judge the communication quality with a simple configuration.

Abstract: In a method for reducing the dynamic range of a multicarrier transmission signal (12?) which is formed in a transmitter and is composed of two or more carriers, the various signal structure timings of the carriers are determined. A delay unit (100; D0, D1, . . . , DN-1) is then used to set a delay profile between the signal structure timings of various carriers, in such a manner that the signal structures of different carriers or substructures of them are not aligned in time with respect to one another.

Abstract: Disclosed is a method and apparatus for transmitting data in a cellular communication system including at least one base station that communicates with a plurality of mobile stations through a given frequency band. The method and apparatus divides the frequency band into at least two subcarrier groups each including a plurality of subcarriers; allocates at least one subcarrier group to each mobile station, and changes the subcarrier group allocated to each mobile station according to a predetermined period; and codes data to be transmitted to each mobile station with a plurality of codes, and transmits modulation symbols obtained by performing inverse fast Fourier transform (IFFT) on a plurality of subcarriers of the allocated subcarrier group.

Abstract: A solution for determining in a radio receiver a data sequence indicating transmission parameters of a frame before receiving the whole frame in the radio receiver in order to speed up processing of the data in the frame. According to the provided solution data is received in one or more time intervals, the data being part of a transmitted data sequence indicating transmission parameters of a frame. The possible data sequences are known to the radio receiver. The received data is compared with corresponding data of each known data sequence, and, on the basis of the comparison, the data sequence which is determined to be closest to the received data is selected. The transmission parameters of the frame are determined based on the selection.

Abstract: A system and method is shown for automatic frequency correction in a receiver, where the number of clock cycles in a baseband data signal, such as an I or Q channel of the receiver or an XOR of the I and Q channels, for a “1” state and a “0” state of a received data signal are each determined and the difference between the two is used to calculate a subsequent frequency offset correction value. The subsequent frequency offset correction value is added to a current offset correction value to obtain an actual offset correction value. The actual offset correction value is then used to adjust the frequency of the receiver clock.

Abstract: Embodiments of an adaptive in-phase (I) and/or quadrature-phase (Q) imbalance correction for multicarrier wireless communication systems is generally described.

Abstract: Improved techniques for acquiring symbol boundary timing at a receiver of a multicarrier data transmission system during a training sequence are disclosed. One aspect is symbol boundary determination at a receiver wherein minimal interference is used as a criterion in selecting from a plurality of potential symbol boundary timings. The symbol boundary determination at the receiver can be performed in a time domain or a frequency domain manner. Another aspect pertains to an improved training sequence wherein pairs of identical symbols are transmitted by a transmitter. These symbols can be supplied to the transmitter in a time domain or a frequency domain manner.

Abstract: A wireless transmit receive unit (WTRU) provides facilitation of cell search. In one embodiment, received samples are split into a plurality of sample sets for processing. Each of the sets is processed and an accumulated result is divided by an estimated noise value. In another embodiment, a code correlator correlates the received signal with a primary synchronization code and an auxiliary code correlator having a same length as the code correlator correlates the received signal with a code having a low cross correlation with the primary synchronization code. In another embodiment, a division of an accumulated result with a noise estimate is performed using indexes of the most significant bits.

Abstract: A method for processing control information in a wireless communications system is described in which portions of the control information are separately encoded and decoded such that transmission format information for a corresponding data transmission can be determined with a reduced set of decoded control information. The control information is convolutionally coded using either a single set of tail bits or by judiciously dispersing the tail bits among different portions of the encoded signaling information.

Abstract: An FSK receiver comprising: 1) demodulation circuitry for receiving an incoming FSK signal and generating a baseband signal comprising an amplitude modulated symbol stream, of Logic 0 symbols and Logic 1 symbols having a data rate, R; 2) auto-correlation circuitry for sampling the baseband signal S times during each symbol and generating an auto-correlation function comprising a sample stream of N-bit samples having a data rate, S×R, and having positive-going peaks approximately coinciding with the center of the Logic 1 symbol in a 010 sequence in the baseband signal and negative-going peaks approximately coinciding with the center of the Logic 0 symbols in a 101 sequence in the baseband signal; and 3) decision circuitry for receiving the auto-correlation function and deciding a logic level of a first symbol as a function of: 1) a comparison of a signal level of a center sample of the first symbol and a mean signal level of the auto-correlation function and 2) a comparison of the signal level of the center sa

Abstract: Embodiments of a low intermediate frequency system and method are disclosed. In one embodiment, among others, a method for operating a receiver is disclosed that comprises receiving a radio frequency signal, downconverting the radio frequency signal to a downconverted signal comprising an in-phase component and quadrature component, and estimating a gain and phase imbalance between the in-phase component and the quadrature component.

Abstract: The present invention relates generally to communication systems, both wired and wireless, employing a continuous phase modulation (“CPM”) waveform with a minimum shift keying (“MSK”) preamble. The present inventive system and method uses information from contiguous Fourier Transforms taken on contiguous data blocks to determine baud rate, phase, frequency offset, and bit timing of the CPM waveform or can be used to determine the frequency of continuous wave waveform. More particularly, the inventive system and method is applicable to the military satellite communications UHF frequency band for deciding whether a signal of interest is.

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

Abstract: Methods and apparatus demodulate and decode a plurality of AM and FM arriving signals, which permit, for example, a utility data-collecting unit to concurrently receive and decode transmitted signals of legacy transmitters as well as more recent FM based transmitters, or signals arriving from hybrid systems configured to transmit both AM and FM.

Abstract: A method for effectively allocating a transmission power and a method for transmitting SCH are disclosed. In this case, the transmission power of the SCH, which is important for initial cell search of the user equipment, is increased but is not allocated to a predetermined frequency region within one OFDM symbol to obtain the increased transmission power, thereby minimizing an influence on transmission of other channels within one OFDM symbol.