Abstract: An approach is provided for correcting a reference clock of a GPS receiver. The approach involves determining one or more frequency offset values. The approach also involves determining one or more codes associated with one or more satellites. The approach further involves determining a second code associated with the one or more satellites. The approach additionally involves determining one or more delay values between the second code and the one or more first codes. The approach also involves determining one or more proportional values based on the one or more delay values and a determined correlation. The approach further involves determining one or more correlation peak values and determining one or more estimated frequency offset error values based on the one or more correlation peak values. The approach additionally involves causing a calibrated reference clock frequency value to change to a recalibrated reference clock frequency value based on the estimated frequency offset error values.

Abstract: A frequency offset acquisition method includes: receiving a specific sequence signal transmitted through a channel; shifting a frequency of the specific sequence signal at a plurality of different frequencies in frequency domain to thereby generate a plurality of shifted sequence signals respectively; and determining an estimated frequency offset value between a transmitter and a receiver according to the shifted sequence signals.

Abstract: A system and method are provided for implementing improved frequency estimation for wireless communication that involves lower power transmissions with reduced signal-to-noise ratios for receivers particularly in systems configured according to the pending IEEE 802.11ah standard. These systems and methods provide frequency estimation over that prescribed for devices operating according other IEEE 802.11 standards and the proposed frequency estimator specified for IEEE 802.11ac systems. The disclosed techniques use schemes that reuse a short training field (STF) stored in memory, employ joint STF-long training field (LTF) estimation, use portions of a guard interval (GI), and create of multiple-phase estimates, with different symbol separation to improve a signal-to-noise ratio of the frequency estimate.

Abstract: Systems, methods, and other embodiments associated with preamble detection based on repeated preamble codes are described. According to one embodiment, an apparatus is provided that wirelessly receives a signal and calculates a differential output corresponding to a multiplication of the signal and a delayed version of the signal. A cross correlation is performed between the differential output and a known preamble pattern to produce a cross correlation output. One or more peaks are detected in the cross correlation. The detected peaks are used in subsequent processing to detect the known preamble pattern in the wirelessly received signal.

Abstract: Receiver synchronization techniques (RST), contributing more accurate synchronization of receiver clock to OFDM composite frame combined with much faster acquisition time and better stability of the receiver clock, and phase and frequency recovery techniques, comprising a software controlled clock synthesizer (SCCS) for high accuracy phase & frequency synthesis producing synchronized low jitter clock from external time referencing signals or time referencing messages wherein SCCS includes a hybrid PLL (HPLL) enabling 1-50,000 frequency multiplication with very low output jitter independent of reference clock quality.

Abstract: A configurable network adapter has N analog front ends, each generating a receiver output and a transmitter input. In a first mode of operation, the analog front end receiver outputs are coupled to a MIMO equalizer, which is coupled to an outer receiver and to a first MAC input, with the first MAC having an output coupled to an outer transmitter, a MIMO modulator, and to the analog front end transmitter inputs. In a second mode of operation, one or more of the analog front ends is directed to a SISO modulator fed by a second outer transmitter coupled to a second MAC transmitter output. An associated one or more of the analog front end receivers is coupled to a SISO equalizer, and thereafter to an outer receiver and to the second lower MAC, thereby providing a first mode for a single MIMO adapter and a second mode for a MIMO plus independent PAN interface.

Abstract: In an embodiment of the invention, a frequency divider in a phase-locked loop (PLL) circuit is provided power from the power supply that provides power to a transmission circuit. The PLL is configured to receive a first direct current (DC) reference voltage, a second DC voltage and a reference clock signal. The PLL is configured to generate a transmission clock signal. A transmission circuit is configured to receive the transmission clock signal, the second DC voltage and a data bus where the data bus includes a plurality of data bits in parallel. The transmission circuit transmits data serially.

Abstract: A method is provided. A multi-amplitude signal is received and downconverted so as to generate I and Q signals using a local oscillator signal. The I and Q signals are equalized, and the equalized I and Q signals are digitized. First and second gains are adjusted with the second and first digital signals, respectively, and applied to the equalized I and Q signals, respectively. The difference between the first and second amplified signals is determined, and an error signal is generated from the difference between the first and second amplified signals. The local oscillator signal is then adjusted with the error signal.

Abstract: A method of estimating a frequency offset based on a training symbol in a receiver of an orthogonal frequency division multiplexing (OFDM) system, includes receiving a first training symbol having a periodicity and a predetermined second training symbol, and calculating a correlation value for the first training symbol based on a coherence phase bandwidth (CPB). The method further includes determining a position of a peak value from the correlation value for an integer multiple frequency offset candidate based on a threshold value, and calculating a correlation value for the second training symbol based on the CPB. The method further includes estimating a position corresponding to a maximum value of the correlation value for the second training symbol as the frequency offset based on the position of the peak value.

Abstract: Apparatuses, methods and systems for mitigating carrier offset of a received signal are disclosed. One embodiment of a receiver includes a receiver chain operative to receive a communication signal from a desired transmitter, and a controller operative to determine a carrier offset correction based on prior reception of communication signals from the desired transmitter. The receiver chain is operative to generate a carrier offset corrected received signal by applying the carrier offset correction to the received communication signal, and a correlation processor operative to correlate the carrier offset corrected received communication signal with a known sequence.

Abstract: A fast and efficient automated satellite constellation detection process can be implemented at least in part independent of in-band data in the satellite signal. The automated detection process iterates through a set of various predefined transponder settings to detect one or more accessible satellite constellations through each satellite dish connected directly or through a switch to a satellite receiver. The process determines whether the satellite receiver is able to lock onto a satellite signal at each transponder setting. Based on the combinations of which satellite constellations are available at each transponder setting, the process allocates a specific satellite constellation to each satellite dish. In one implementation, channel information can be used to further refine the detection and identification of accessible satellite constellations for each satellite dish.

Abstract: Compressing a variable phase component of a received modulated signal with a second harmonic injection locking oscillator, and generating a delayed phase-compressed signal with a fundamental injection locking oscillator, and combining the phase-compressed signal and the delayed phase-compressed signal to obtain an estimated derivative of the variable phase component, and further processing the estimated derivative to recover data contained within the received modulated signal.

Abstract: The invention discloses an adaptive phase shift method in a multi-carrier system, comprising: generating a group of one or more new phase values for corresponding one or more phase shift carriers, PSCs, based on quantization phase values; calculating and comparing a backward maximum power in an evaluation path with the group of one or more new phase values in one timeslot and a forward maximum power in a working path with current phase values in the timeslot; and adjusting phase of the PSCs based on the group of one or more new phase values if the calculated backward maximum power is less than the calculated forward maximum power. An adaptive phase shift apparatus is also disclosed. With the invention, complexity of the implementation is reduced and a small DPS block resource, low Hardware cost, low power consumption is also achieved.

Abstract: A method and apparatus can be configured to receive at least one channel state information reference symbol. The method can also include determining a negative timing offset estimate and a positive timing offset estimate. The negative timing offset estimate and the positive timing offset estimate are based on the at least one channel state information reference symbol. The method can also include receiving a demodulation reference symbol. The method can also include selecting either the negative timing offset estimate or the positive timing offset estimate based on the demodulation reference symbol.

Abstract: An arrangement and method for digital frequency synthesis. The arrangement includes a device for phase quantization structured and arranged to operate based on a reference clock and a phase increment value, and a device for amplitude quantization structured and arranged to operate based on a reference clock and a phase increment value. The arrangement also includes a device for noise shaping of a phase arranged in the signal path after the device for phase quantization, a device for noise shaping of an amplitude arranged in a signal path after the device for amplitude quantization, and a phase to amplitude converter.

Abstract: A broadcast receiver suitable for receiving broadcast signals transferred by use of signal format of IBOC system. The broadcast receiver comprises a receiving means that holds information related to channels that can be acquired by a digital signal decoding process. If information related to a channel is to be used and is held by the information holding means, then it is used.

Abstract: An ultra low power radio receiver architecture based on phase locked loop is provided. Embodiments of an ultra low power radio receiver architecture based on phase locked loop can detect a complex modulated MSK signal with only a single path receiver chain. According to an embodiment of the present invention, the overall power consumption of the radio receiver in the present invention can be reduced by almost fifty percent compared to that of the conventional complex path radio receiver architecture. The radio receiver architecture of the invention is suitable for the ultra low power radio application such as wireless sensor networks (WSN).

Abstract: A method and system provide frequency offset compensation in a wireless communication device. A frequency offset compensation module (FOCM) correlates a received reference signal with sub-replica reference sequences to obtain a vector of matched filter output values associated with a time offset identified by a correlation time index value. The FOCM determines a correlation score vector using a combined energy associated with matched filter output values. The FOCM then determines a first phase difference based on matched filter output values corresponding to adjacent sub-replica sequences. The FOCM computes a second phase difference by linearly combining a selected first phase difference and at least one neighbor first phase difference having a second correlation time index value that differs from a first correlation time index value of the selected first phase difference. The FOCM uses the second phase difference to provide compensation for a frequency offset associated with received signals.

Abstract: A technique to provide hybrid compensation to correct for drifts in a reference frequency output from a digitally-controlled crystal oscillator (DCXO). A first compensation is provided to the DCXO to adjust for overlap or discontinuity of the reference frequency caused by switching capacitors in the capacitor array that controls drift of the reference frequency output. The second compensation is obtained at a phase-locked loop (PLL) that receives the reference frequency signal from the DCXO. The second compensation adjusts the PLL to adjust for variations of the reference frequency that remain after performing compensation in the DCXO.

Abstract: A receiver for a multi-channel communication system can include a down-converter device, an analog-to-digital converter (ADC), and a plurality of digital channel selection devices. The down-converter device can be configured to down-convert a plurality of analog signals from the multi-channel communication system to a plurality of corresponding low intermediate frequency (IF) signals. The ADC can be configured to convert the plurality of corresponding low-IF signals to a plurality of digital signals. Further, each digital channel selection device from the plurality of digital channel selection devices can be configured to select a digital signal corresponding to a channel of interest from the plurality of digital signals for further processing.

Abstract: In a method for estimating a carrier frequency offset (CFO) between a transmitting device and a receiving device, a data unit is received. The data unit includes aperiodic sequence. An initial phase shift value of a phase shift between adjacent periods of the periodic sequence is generated, and a plurality of cross-correlations using at least one period of the periodic sequence are performed to generate a plurality of cross-correlation results. Each cross-correlation is performed using one of a plurality of possible actual phase shift values. An actual phase shift value is selected, based on the plurality of cross-correlation results, from the plurality of possible actual phase shift values. An estimate of the CFO is generated based at least in part on one of the initial phase shift value or the actual phase shift value.

Abstract: The invention provides a method and an apparatus for estimating frequency deviation, the method comprising: after receiving a sub-frame, transforming a downlink synchronized code of the sub-frame to a frequency domain, and performing a correlation operation between the transformed downlink synchronized code and a local frequency domain synchronized code to obtain a conjugate downlink synchronized code sequence; judging a location of a maximum value in the conjugate downlink synchronized code sequence, and calculating a frequency deviation value according to the location of the maximum value. The estimating method provided in the invention can realize a stable work with no need of a precise sampling value location, an accurate timing synchronization, or even obtaining the information for the multi-path distribution and locations.

Abstract: An electronic device may include sensitive circuitry such as radio-frequency receiver circuitry. A noise source may produce radio-frequency interference that can disrupt operation of the sensitive circuitry. The noise source may include a first transmitter such as a cellular telephone transmitter and as second transmitter such as a wireless local area network transmitter. Interference may be produced by simultaneous operation of the first and second transmitters. The radio-frequency receiver circuitry may be satellite navigation system receiver circuitry that includes one or more satellite navigation receivers. The impact of interference may be reduced by blanking the satellite navigation system receiver, by imposing a duty cycle limitation on the second transmitter, by switching between alternative receivers in the satellite navigation system receiver circuitry, by using an interference-dependent cross-correlation protection scheme, or by using a combination of these schemes.

Abstract: A data processing device includes a clock converter, a data converter, and an error detector. The clock converter is configured to receive a first clock signal, convert the first clock signal into a second clock signal, and output the second clock signal. The data converter is configured to receive first data, convert the first data into second data using the second clock signal, and output the second data. The error detector is configured to check whether the first clock signal is in a first clock state or a second clock state upon the first data transitioning to a first data state, and output an enable signal to the clock converter upon determining that the first clock signal has transitioned to the first clock state from the second clock state.

Abstract: A receiver includes a first local oscillator (LO), with a pair of in-phase and quadrature (IQ) mixers coupled to the first LO and configured to generate complex IQ signals having an IQ imbalance. The receiver also includes a second LO, with a complex mixer coupled to the second LO and configured to mix the complex IQ signals and generate intermediate frequency (IF) signals based thereon. A controller is coupled between the pair of IQ mixers and the complex mixer and configured to set the first LO and the second LO so that the complex IQ signals and an interfering signal generated due to the IQ imbalance of the complex IQ signals have a same sign and non-overlapping bands at an input of the complex mixer.

Abstract: Embodiments of user equipment and methods for determining IQ imbalance parameters are described. In some embodiments, a method for determining in-phase (I) and Quadrature (Q) imbalance (IQ imbalance) parameters based on a known signal in a dual-carrier receiver using at least one controllable frequency offset includes receiving a known signal modulated onto a first radio frequency (RF) carrier frequency and a second RF carrier frequency different than the first RF carrier frequency. The known signal is downconverted to a baseband signal for the carriers by conversion from the respective RF carrier frequencies to an intermediate frequency (IF) using a common RF local oscillator (LO) and by further conversion from IF to baseband using carrier specific IF LOs, where a controllable frequency offset is used. Any controllable frequency offset is removed from the baseband signal for the first and second carriers to produce representations of the received signals.

Abstract: Apparatuses, methods and systems of synchronizing a receiver to a desired signal are disclosed. One method includes obtaining synchronization information of an interfering signal, and adjusting an out-of-band response of a receiver filter based at least in part on the synchronization information of the interfering signal, wherein the in-band response of the receiver filter is determined by frequency components of the desired signal.

Abstract: Circuitry separates a modulation signal into digital sign and magnitude signal components. The digital magnitude signal is converted to an analog magnitude signal. The analog magnitude signal is the mixed with an in-phase or quadrature carrier signal under the influence of the digital sign signal and routed to a driver output stage.

Abstract: A technique includes using a receiver to process a radio frequency (RF) signal to downconvert spectral content from a first frequency band to a second frequency band to generate an intermediate frequency (IF) signal. The technique includes controlling a location of the second frequency band based at least in part on a selectable channel bandwidth of the receiver.

Abstract: An apparatus and a method for estimating a channel in a broadband wireless access system. A receiving apparatus includes a first channel estimation filter having a tap coefficient which is channel-adaptively variable, the first channel estimation filter acquiring a channel impulse response by filtering received pilot symbols, a second channel estimation filter having a fixed tap coefficient, the second channel estimation filter acquiring a channel impulse response by filtering received pilot symbols, and a selector which selects the operation of one of the first and the second channel estimation filters according to channel correlativity.

Abstract: Disclosed herein is a reception apparatus including: a reception section configured to receive a signal at a frequency being changed; and a control section configured such that before changing the frequency to receive the signal, the control section stores control information about the reception section receiving the signal at the current frequency as last control information and that upon receiving again the signal at the frequency in effect before the change, the control section sets the last control information to the reception section as an initial value.

Abstract: An antenna amplifier, receiving system, operating method, and use of a receiving system, is provided.

Abstract: A symbol rate detection apparatus includes an analog-to-digital converter (ADC), a coarse detection module, a mixer, a down-sampling module, and a fine detection module. The ADC converts an analog input signal to a digital input signal at an original sampling frequency. The coarse detection module estimates a carrier frequency offset and a coarse symbol rate according to the digital input signal. The mixer adjusts the frequency of the digital input signal according to the carrier frequency offset to generate a frequency-compensated signal. The fine detection module determines a fine symbol rate according to the frequency-compensated signal.

Abstract: A desired signal and interfering signal are transmitted in the same timeslot and on the same frequency using an Adaptive Quadrature Phase Shift Keying (AQPSK) modulated carrier. When the Sub-Channel Power Imbalance Ratio (SCPIR) for the AQPSK modulated carrier is large and favors the interfering signal, the interfering signal is demodulated first to obtain demodulated soft bits. The demodulated soft bits corresponding to the interfering signal are then used to estimate receiver control parameters, such as Doppler shift, frequency offset, timing error, gain, etc. Using the demodulated soft bits corresponding to the interfering signal improves the accuracy of the receiver control parameters when the SCPIR is large, and results in better overall performance of the receiver.

Abstract: An apparatus includes: an offset adjustment unit supplying an offset correction signal corresponding to a frequency switching to an adder unit receiving output from a mixer; a timing adjustment unit adjusting the timing of a frequency switching signal supplied to a local oscillator and the timing of an offset correction amount switching signal supplied to the offset adjustment unit for changing an offset amount in correspondence with the frequency switching in the local oscillator; a noise amount measurement and calculation unit receiving a signal obtained by amplifying and filtering the signal from the adder unit, to measure a noise amount of the signal and generates a timing determination signal based on the noise amount; and a control unit controlling frequency switching signal timing and the offset correction amount switching signal supplied to the timing adjustment unit, based on the timing determination signal from the noise amount measurement and calculation unit.

Abstract: A method for demodulating a radio frequency signal according to one embodiment includes receiving digital signals derived from a radio frequency signal; converting the digital signals to baseband signals; generating a frequency error signal using the baseband signals during an acquisition period; and shifting a frequency of the digital signals towards zero frequency error during the acquisition period using the frequency error signal, with the proviso that the digital signals are not phase locked during the shifting. Such methodology may also be implemented as a system using logic for performing the various operations. Additional systems and methods are also presented.

Abstract: A semiconductor device includes a one-segment tuner I/F that is connected to a one-segment tuner, a tuner I/F that is connected to a digital terrestrial tuner, a decoder that selectively decodes a first broadcast signal supplied from the one-segment tuner I/F and a second broadcast signal supplied from the tuner I/F, a general purpose processor that is provided separately from the decoder and decodes the first broadcast signal, and a switch unit that, based on signal intensity of the second broadcast wave, switches the decoding by the decoder between the first broadcast signal and the second broadcast signal while the general purpose processor is decoding the first broadcast signal. The one-segment tuner I/F, the tuner I/F, the decoder, the general purpose processor, and the switch unit are integrated on one chip.

Abstract: A method for supporting wireless communication over a physical channel in a mobile broadband system includes providing an estimate of the channel and obtaining a channel autocorrelation function of a channel impulse response of the channel. The method also includes expressing the channel autocorrelation function as a zero order Bessel function and applying Taylor expansion to the zero order Bessel function. Additionally, the method includes performing derivation of the channel autocorrelation function to obtain an estimate of the maximum Doppler frequency and using the obtained estimate of the maximum Doppler frequency to compensate for a current Doppler effect in a receiver receiving the signals.

Abstract: Modern digital signals include framing. A known sequence of transmission symbols (Unique Word (UW)) included in the transmitted signal may be used by a receiver for framing synchronization. A receiver configured to receive such a signal may be configured to detect the UW even when the signal is received with some frequency uncertainty (e.g. offset or error). A method is presented for fast acquisition of symbol and/or frame timing of a signal, including in the presence of frequency uncertainty. In some embodiments, the presented method may be used for determining a frequency offset of the received signal and a location of a unique word (UW) within a frame of the received signal, wherein said determining is based on a two-dimensional search map.

Abstract: Compressing a variable phase component of a received modulated signal with a second harmonic injection locking oscillator, and generating a delayed phase-compressed signal with a fundamental injection locking oscillator, and combining the phase-compressed signal and the delayed phase-compressed signal to obtain an estimated derivative of the variable phase component, and further processing the estimated derivative to recover data contained within the received modulated signal.

Abstract: Systems and methods for frequency offset estimation are provided. A channel impulse response and multi-user signal parameter are jointly estimated. Based on the multi-user signal parameter, a determination is made as to whether the signal contains a single-user signal or a multi-user signal. Then, frequency offset estimation is performed based on this determination. For example, noiseless sample estimates are generated depending on whether the signal is a single-user signal or a multi-user signal.

Abstract: Disclosed is an apparatus and method for detecting a code. The code detecting apparatus may include a detector to detect symbol synchronous timing information associated with a PSS code from a first signal received during a predetermined first period, a compensator to extract and buffer the PSS code and the SSS code based on the symbol synchronous timing information detected from a second signal received during a predetermined second period, and compensate for a frequency offset with respect to the buffered PSS code, and a processor to re-detect the symbol synchronous timing information based on the PSS code in which the frequency offset is compensated for, and extract the buffered SSS code using the re-detected symbol synchronous timing information.

Abstract: A communication receiver which applies signal processing for quantitatively estimating receive signal factors such as communication channel quality, signal characteristics, and overall system received bit error rate (BER) or packet error rate (PER) and which applies a general algorithm for mapping these estimated factors to control receiver performance and minimize power consumption.

Abstract: Digital IQ imbalance estimation and compensation is facilitated by shaping the frequency response of receiver branches. In particular, in a multi-carrier receiver, the frequency response of signal processing elements in at least one receiver branch is set to not fully attenuate received signals in a frequency band of interest. The frequency band of interest is greater than the carrier bandwidth of the received signal processed by that receiver branch. In some embodiments, the received signal is not attenuated, and adjacent interfering signals are partially attenuated. This allows information regarding the interfering signals to appear in an IQ imbalance-induced, inter-carrier image of the signals in anther receiver branch, facilitating digital estimation and compensation of IQ imbalance.

Abstract: A communication system includes: a frequency synthesizer, configured to reference a radio frequency (RF) signal, in a device including: a ring oscillator with track-and-hold circuit electrically connected to a reference clock, a bank of comparators, electrically connected to the ring oscillator with track-and-hold circuit, configured to measure a coarse timing, and an analog-to-digital converter, electrically connected to the ring oscillator with track-and-hold circuit, configured to generate a fine timing; a communication interface, electrically connected to the frequency synthesizer, is configured to receive a device transmission; and a control unit, electrically connected to the communication interface, is configured to display a receiver data from the a radio frequency (RF) signal.

Abstract: A signal processing apparatus includes a signal generating block arranged to generate a target estimated signal of a specific signal component in an input signal. The signal generating block includes a reference signal generating circuit, a signal processing circuit, and a signal adjusting circuit. The reference signal generating circuit is arranged to generate a reference estimated signal for the specific signal component in the input signal. The signal processing circuit is coupled to the reference signal generating circuit, and arranged to process the reference estimated signal and accordingly generate a signal processing result. The signal adjusting circuit is coupled to the signal processing circuit and the reference signal generating circuit, and arranged to output the target estimated signal by adjusting the reference estimated signal according to the signal processing result.

Abstract: The present invention aims at eliminating the effects of frequency offsets between two transceivers by adjusting frequencies used during transmission. In this invention, methods for correcting the carrier frequency and the sampling frequency during transmission are provided, including both digital and analog implementations of such methods. The receiver determines the relative frequency offset between the transmitter and the receiver, and uses this information to correct this offset when the receiver transmits its data to the original transmitter in the return path, so that the signal received by the original transmitter is in sampling and carrier frequency lock with the original transmitter's local frequency reference.

Abstract: A filter auto-calibration system includes a multi-clock module. The multi-clock module includes a multi-clock generator that is configured to generate a clock signal with a variable frequency based on a channel setting. There is at least one filter to be calibrated. An auto-calibration control module is configured to control calibration of the at least one filter based on the channel setting. The multi-clock module is configured to supply the variable frequency clock signal to the at least one filter and to the auto-calibration control module, and the at least one filter is coupled to the auto-calibration control module.

Abstract: A cognitive radio signal processing method suitable for single receiver devices where interference is mitigated using projection of received multi-dimensional signal space to maximize SNR by orthogonalizing interference is described. The method is based on a well-known LMS solution that is computed from received multi antenna and multicarrier signals in a novel way. This method solves the requirement of multiple RF chains in low cost handsets by introducing a protocol synchronous antenna switcher that allows, for example, a LTE handset with a single antenna to benefit from algorithms that typically require multiple receivers for the same frequency, i.e. MIMO.

Abstract: An automatic frequency control apparatus and method are provided. If the number of frequency error measurements is smaller than a reference number for frequency estimation compensation, the automatic frequency control apparatus performs frequency compensation using a frequency error value, and if the number of frequency error measurements is equal to or greater than the reference number for frequency estimation compensation, the automatic frequency control apparatus performs frequency compensation by estimating a frequency value that is to be used until the next frequency control period. Therefore, since frequency errors are accurately corrected in a high-speed mobile environment, an excellent channel environment may be maintained, and accordingly an occurrence frequency of re-transmission may be lowered, resulting in ensuring a high data rate.