Abstract: Apparatuses and methods are disclosed for decoding expected block messages transmitted as radio signals over an air interface in interleaved bursts from a shorter received burst. A method for detecting certain expected messages from received bursts is described, comprising: receiving a one to m bursts of n bursts of an interleaved block message; retrieving stored values for the expected m+1 to n bursts of the interleaved block message; forming an expected interleaved block message; deinterleaving and decoding the expected block message; determining from an error checking whether the expected block message is valid; and if valid, indicating the expected block message was received after receiving only the m bursts. Apparatuses are described for a receiver configured to detect an expected message after receiving m transmitted bursts of an interleaved n burst block message. The expected message may be an empty paging channel or broadcast message.

Abstract: Method, communication system, receiver, baseband processor and computer program for recovering data from a received OFDM-signal containing recurrent redundant information where part of the recurrent redundant information is used to maximize the SINR (Signal to Interference plus Noise Ratio) of the received OFDM-signal.

Abstract: In one embodiment, the present invention is a method for reducing the peak-to-average power ratio (PAPR) of a multi-carrier modulated symbol, such as an orthogonal frequency division multiplexed (OFDM) symbol. The method first transforms a set of data symbols into a multi-carrier modulated symbol. The method then uses the multi-carrier modulated symbol and a gradient-descent algorithm to generate a set of symbols for PAPR-reduction tones. The data symbols and the PAPR-reduction symbols are then transformed to generate an updated multi-carrier modulated symbol. The PAPR-reduction symbols are iteratively updated until a terminating condition occurs (e.g., an acceptable PAPR is achieved for the multi-carrier modulated symbol).

Abstract: A wireless receiver realizes multi-band and multi-mode operations while reducing power consumption of a local oscillator. The receiver includes the local oscillator for discontinuously changing a band of a local oscillation signal corresponding to a frequency band of an RF signal to be received and outputting the local oscillation signal, a frequency converter for converting the RF signal into an IF signal by using the local oscillation signal, and a demodulator for demodulating the IF signal. The local oscillator detects a frequency variation range of the local oscillation signal, obtains a frequency equivalent to an integral multiple of a symbol rate from the frequency variation range, and outputs the local oscillation signal having a local oscillatory frequency, causing a center frequency of a channel to be received, which channel is included in the intermediate frequency signal, to be equivalent to the integral multiple of the symbol rate.

Abstract: Disclosed is a binary signal modulator for minimizing deterioration of receiving performance caused by phase error. The binary signal modulator receives binary signals, and converts the binary signals into complex symbols according to a predetermined mapping relation. Here, the mapping relation is generated when a plurality of mapping symbols are arranged on a plurality of trajectories so that the distance between the mapping symbols is greater than or equal to a predetermined distance and the phase between the mapping symbols is greater than or equal to a predetermined angle from among the trajectories starting from a plurality of points on the complex plane, and a distance between the trajectories is greater than or equal to the minimum distance from among the distances between the points.

Abstract: Techniques for detecting and demodulating data transmissions in wireless communication systems. In one aspect, a decision-directed detector detects for data transmissions in a received signal by utilizing received data symbols as well as received pilot symbols. The decision-directed detector may be designed to perform differential detection in the frequency domain or coherent detection in the time domain, and may be used with multi-carrier modulation (e.g., OFDM). In another aspect, an adaptive threshold is used to perform detection of received data transmissions. A threshold may be determined for each data transmission hypothesized to have been received. The threshold may be computed, for example, based on the signal plus noise energy of the hypothesized data transmission.

Abstract: The invention relates to methods for transmitting and receiving a data bit stream in a communication system using a 16-QAM constellation. Further, an apparatus for performing the methods is provided. To provide a modulation and coding scheme using a signal space expansion and 16-QAM which improves the bit-error rate in comparison to QPSK modulated signals and still provides the possibility to implement coders and decoders with low complexity the invention suggests the use a 16-QAM constellation with specially selected mapping rules together with repetition coding (signal space expansion) and interleaving of the data stream to be transmitted.

Abstract: A timing skew estimation system is disclosed that includes a plurality of interleaved analog-to-digital converter circuits (ADCs), a timing mismatch estimation unit, and a correction unit. The timing mismatch estimation unit calculates a correlation between each of the plurality of ADCs. Then the timing mismatch estimation unit calculates a cost function for each of the plurality of ADCs, except the reference ADC. The timing mismatch estimation unit further calculates a gradient for each of the plurality of ADCs, except the reference ADC.

Abstract: A method and apparatus of high speed multi-dimensional signaling via a modem has a processing method of utilizing prolate pulses to optimize the transmission capacity of the channel. The modem includes a process that segments the channel bandwidth and allocates the power and bit loading in relation to a measure of the noise in each spectral bin. Data are carried over a plurality of frequencies across the channel, and within each spectral bin, a plurality of orthogonal signaling dimensions.

Abstract: A low power BPSK demodulator having a simple architecture, compact design and reliable is provided. The BPSK demodulator includes a first branch (210) having a first mixer (212) and a first low pass filter (214), a second branch (220) coupled to the first branch at the output of the first low pass filter (214) and input of the first mixer (212) and having a second mixer (222), and a third branch (230) coupled to the second branch at the input and output of the second mixer (222) and having a third mixer (232) a second low pass filter (234) and a voltage control oscillator (236), wherein the third branch and the second branch form a charge pumped based phase lock loop that locks onto a carrier frequency of the BPSK demodulator.

Abstract: Spectrum sensing is one of the most challenging problems in cognitive radio systems. The spectrum of interest needs to be characterized and unused frequencies should be identified for possible exploitation in a simple and fast way, allowing the radio to catch up with the changing transmission parameters. A sensing method is presented where primary users are identified by matching the features extracted from the received signal to the a priori information about primary users' transmission characteristics. For estimation of some signal parameters, the cyclostationarity of the transmission spectrum is explored by using a suboptimal maximum likelihood (ML) estimator. The proposed algorithms can be used in cognitive radio for identifying various transmissions and for electronic surveillance.

Abstract: A communication apparatus for a continuous phase modulation signal. The communication apparatus includes a first processing unit configured to generate first information of the continuous phase modulation signal using first symbol data; a symbol converting unit configured to convert the first symbol data into second symbol data or convert the second symbol data into the first symbol data; a symbol storage unit configured to store the second symbol data; a second processing unit configured to second information of the continuous phase modulation signal using the second symbol data stored in the symbol storage unit; a third processing unit configured to generate third information of the continuous phase modulation signal using a modulo operation of an integer related to a modulation index; and an output unit configured to add an output from the third processing unit and an output from the first processing unit and generate the continuous phase modulation signal.

Abstract: A frequency error correction scheme applicable in a receiver of a mobile telecommunication system is presented. The present frequency error correction scheme is carried out in a time domain after an equalization process. The present frequency error correction scheme may be applied to a base station receiving signals transmitted according to a single-carrier frequency division multiple access communication scheme. The separation of different received signals for further processing is carried out in the frequency domain before the equalization and the frequency error correction.

Abstract: A demodulating system (100) for demodulating a phase-modulated input signal (Si) comprises: a complex demodulator (110), having a first input (111) for receiving the phase-modulated input signal (Si) and being designed to perform complex multiplication of this signal with an approximation of the inverse of the phase modulation; a spectrum analyzing device (130) receiving the demodulated product signal produced by the complex demodulator (110) and capable of analyzing the frequency spectrum of the demodulated product signal.

Abstract: An automatic zero-crossing signal demodulation and classification device for rapidly identifying an unknown modulation in a signal identifies an unknown modulation in a signal, demodulates differential phase shift keying signals and automatically recognizes certain phase shift keying signals. This is accomplished by eliminating the unknown term fc in differential phase estimation, introducing a symbol rate tracking mechanism, applying hysteresis nonlinearity to eliminate the phase shaping effect and using a weighted average to estimate the phase difference. Better estimates are accomplished by using the hysteretic nonlinear function to detect the zero-crossing points in eliminating the false detecting of the zero-crossing points caused by the additive noise, and calculating differential phase without directly using the center frequency to simplify the estimation process.

Abstract: A Signal-to-Interference Ratio of a radio channel is estimated in a receiver of a wireless communications system, wherein pilots with reference information are modulated on some sub-carriers in some symbols. At least one parameter for signals received from said first transmitter is detected, and a number (Nf, Nt) of pilots in first groups that can be coherently combined in a second group is determined, and from these a channel estimate (H) for each first group and a first covariance estimate (R) for each second group are determined. A number (M) of first covariance estimates that can be averaged is defined in dependence of the presence of signals from possible interfering transmitters, and a second covariance estimate is determined as an average of said number of first covariance estimates. From the channel estimates and the second covariance estimate a Signal-to-Interference Ratio for each second group is estimated.

Abstract: A receiver and method for receiving and processing a sequence of transmitted symbols in a digital communication system utilizing soft pilot symbols. A set of soft pilot symbols are transmitted with higher reliability than the remaining symbols in the sequence by modulating the soft pilot symbols with a lower order modulation such as BPSK or QPSK while modulating the remaining symbols with a higher order modulation such as 16QAM or 64QAM. The receiver knows the modulation type and location (time/frequency/code) of the soft pilot symbols, and demodulates them first. The receiver uses the demodulated soft pilot symbols as known symbols to estimate parameters of the received radio signal. Unlike traditional fixed pilots, the soft pilots still carry some data. Additionally, the soft pilots are particularly helpful in establishing the amplitude reference essential in demodulating the higher order modulation symbols.

Abstract: There is provided a method that comprises identifying a parasitic signal transfer in a filter using a signal-directed graph; and adding compensation paths to the filter to reduce or eliminate the effect of the parasitic signal transfer A corresponding filter is provided which comprises a plurality of amplifier stages that generate one or more filter poles; at least one component coupled to at least one of the amplifier stages, the component causing a parasitic effect in the filter; and means for applying a compensation current to the at least one amplifier stage to reduce or eliminate the parasitic effect.

Abstract: A set of one or more samples is received. Using a first signal processor associated with a first phase offset, a first decision and a first error value are generated using the set of samples. Using a second signal processor associated with a second phase offset, a second decision and a second error value are generated using the set of samples. This includes interpolating the set of samples to obtain a set of interpolated samples at the second phase offset and generating the second decision and the second error value using the set of interpolated samples at the second phase offset. A selection associated with the first decision and the second decision is made based at least in part on the first error value and the second error value.

Abstract: The communications terminal and acquisition method is for use with Continuous Phase Modulation (CPM) and Phase Shift Keying (PSK) modulation-type signals, each modulation-type signal having a respective preamble phasing sequence. The communications terminal may include a wireless communications device to receive a modulated signal having one of the CPM and PSK modulation types, and having a symbol rate. A controller may be included to cooperate with the wireless communications device to perform a transform process, such as a Fourier Transform (FT) process, on the received modulated signal to detect the modulation type and the symbol rate of the received modulated signal based upon the preamble phasing sequence. Carrier phase and frequency of the received modulated signal may be estimated based upon bin amplitudes. Also, symbol timing may be estimated based upon a phase difference between tones associated with the preamble phasing sequence.

Abstract: A receiver according to one embodiment includes a frequency control unit configured to receive a stream of samples including a plurality of received instances of a transmitted signal. The frequency control unit is configured to output a first correction signal (e.g. indicating a rotation) that is based on more than one of the received instances and a second correction signal (e.g. to control an oscillator) that is also based on more than one of the received instances. In some embodiments, a controlled oscillator is used to receive and/or transmit another signal, such as a signal received from a GPS space vehicle. In other embodiments, the received instances are from a GPS signal. In further embodiments, a fixed-frequency oscillator is used, and the second correction signal is used to receive and/or transmit another signal, such as a GPS signal.

Abstract: A duplicating section duplicates a bit sequence to be input, and a 16 QAM section modulates a bit sequence of a duplicating source to form a symbol, a 16 QAM section modulates the duplicated bit sequence to form a symbol, an S/P section parallel converts the symbol sequence input in series, an S/P section parallel converts the symbol sequence input in series, and an IFFT section 15 provides IFFT processing to the input symbol sequence. Since each of multiple same bits duplicated by the duplicating section is included in a different symbol, each of the multiple same bits is allocated to each of multiple subcarriers each having a different frequency by IFFT processing. As a result, a multicarrier signal including the multiple same bits each having a different frequency is generated.

Abstract: Provided is a correlation scheme selecting apparatus and method that can acquire initial synchronization efficiently by calculating frequency error criterion threshold between correlation schemes and selecting a correlation scheme for each region when a correlation value is calculated for initial sync in a communication system with carrier frequency errors. The method for selecting a correlation scheme based on a carrier frequency error includes: calculating mis-detection probability values based on a normalized frequency offset for each correlation scheme; determining as a frequency-error criterion threshold a crossing point of graphs of the calculated mis-detection probability values for each correlation scheme; and selecting a correlation scheme based on the determined frequency-error criterion threshold.

Abstract: In one embodiment, a method includes receiving N input streams; generating a recovered clock signal based on the input data bits in the N input streams, the recovered clock signal having a clock frequency and a recovered clock phase; generating a clock signal for each one of the N input streams based on the recovered clock signal having the clock frequency and a respective phase at a respective phase offset relative to the recovered clock phase; detecting a phase difference between each of the N input bit streams and the respective N clock signals; and adjusting the phases of the N clock signals to eliminate the respective phase differences, the adjusting comprising shifting the N respective clock phase offsets such that each of the N clock signals is locked to the input data bits in the respective one of the N input streams.

Abstract: A television tuner employs a single down-conversion architecture to translate VHF/UHF TV signals to various standard IF frequencies. The television tuner includes a harmonic rejection and quadrature mixer and a quadrature mixer. The harmonic rejection and quadrature mixer mixes a first-band signal with a reference signal to output a first pair of in-phase and quadrature-phase signals with a harmonic-frequency component eliminated from the resulting signals. A quadrature mixer mixes a second-band signal with the reference signal to output a second pair of in-phase and quadrature-phase signals. A digital signal processing circuit coupled to both the harmonic rejection and quadrature mixer and the quadrature mixer for selectively processing either the first pair of in-phase and quadrature-phase signals or the second pair of in-phase and quadrature-phase signals to generate an output signal corresponding to a desired channel.

Abstract: A television tuner employs a double quadrature mixing architecture to frequency-translate VHF/UHF TV signals to various standard IF frequencies. In the television tuner, a quadrature mixer converts the input television signal into a first in-phase signal and a first quadrature-phase signal according to a first reference signal, and a double quadrature mixer converts the first in-phase signal and first quadrature-phase signal into a second in-phase signal and a second quadrature-phase signal according to a second reference signal, and a polyphase filter filters the second in-phase signal and second quadrature-phase signal to produce an output signal.

Abstract: A method for performing burst mapping on transmission data by a transmitter in a mobile communication system using a 16-ary Quadrature Amplitude Modulation (16-QAM) modulation scheme is disclosed. The burst mapping method includes generating control information bits and user data bits by encoding input control information and user data; dividing the control information bits and user data bits into more than two bursts; and arranging a Training Sequence Code (TSC) in a center of each burst, placing the coded control information bits in positions adjacent to the TSC, and swapping the user data bits with bits mapped to higher-reliability positions among the control information bits.

Abstract: The present invention relates an apparatus and method of estimating a signal-to-noise ratio (SNR) of a received signal when the received signal has a timing offset. An apparatus for estimating a signal-to-noise ratio (SNR) according to an exemplary embodiment of the present invention includes a fast Fourier transform (FFT) unit that performs a fast Fourier transform on a received signal to convert the received signal into a frequency domain signal; a preamble selector that extracts a preamble from the frequency domain signal; a correlator that correlates the preamble to a preamble reference signal generated by a receiver to calculate a correlation value; an entire power estimator that calculates entire power; a noise power estimator that applies a differential demodulation method to the correlation value to remove a timing offset and calculate noise power; and an estimating unit that uses the entire power and the noise power to estimate the signal-to-noise ratio (SNR).

Abstract: Methods and apparatuses for maximizing power and spectral efficiencies in a wireless communication system are disclosed. The invention is particularly useful for layered modulation applications because power levels for such applications are relatively high. A layered modulation signal comprises an upper and a lower layer signal that interfere with each other within the same frequency band such that the upper layer signal can be demodulated directly from the layered modulation signal, and the lower layer signal can be demodulated after subtracting the first layer signal from the layered modulation signal. The invention applies one or more of the following four signal schemes in a communication signal including varying the symbol rate (rather than the code rate), reducing or eliminating the guard band, reducing excess signal bandwidth and employing layered modulation within the guard band of the legacy signal.

Abstract: A radio communication apparatus and an associated method are provided. The apparatus includes a receiving unit configured to receive first data and second data, which are transmitted from a plurality of antennas for spatial-multiplexing using a plurality of blocks, into which a plurality of consecutive subcarriers in a frequency domain are divided. The apparatus further includes a calculating unit configured to calculate a first absolute CQI value per each of the blocks for the first data and a second absolute CQI value per each of the blocks for the second data, and calculate a relative value of the second absolute CQI value with respect to the first absolute CQI value, per each of the blocks. The apparatus still further includes a transmitting unit configured to transmit the first absolute CQI value and the relative value of the second absolute CQI value in the same block.

Abstract: A method and apparatus for demodulating an input signal, for example, in a communications system, is disclosed. The apparatus includes a signal preconditioner and a demodulator. The signal preconditioner may include a low-pass filter and a hysteretic comparator that are configured to precondition a preconditioner input signal to provide a preconditioner output signal. The modulator may be configured to demodulate the preconditioner output signal.

Abstract: A DC offset correction circuit includes a DC offset detector generating a detection voltage based on a result of a comparison of a first reference voltage and a voltage difference between signals input to the DC offset detector, a comparator comparing a second reference voltage and the detection voltage and a third reference voltage and the detection voltage and outputting first and second comparison signals, respectively, as a result of the comparisons, and an up/down counter performing an up or a down count operation in response to one of the first or second comparison signals and, as a result of the up or down count operation, outputting a signal that causes at least one control signal for canceling a DC offset in a signal input to a receiver to be generated.

Abstract: Embodiment for forming an aggregate signal from a plurality of starting signals, comprising: acquiring said starting signals through respective sensors of a homogeneous sensors group; converting acquired signals in respective digital signals having data represented with a predetermined bits number; processing the digital signals to form aggregate signal. The processing step comprises the operations of: modifying digital signals changing the data format of each such digital signals from a first format to a second format, each data in the second format having been obtained from a respective data in the first format through an operation of permuting the bits position according to a permutation scheme associated with said data and to the specific digital signal comprising that data; forming aggregate signal obtaining said aggregate signal data by means of a bitwise logic operator acting upon said modified digital signal respective data.

Abstract: A method is provided that contemplates including filtered decode values in an RDS/RBDS output signal. The filtered decode values are generated from reliable values. The reliable values are generated from corresponding received values from each of at least two groups of RDS/RBDS data in an RDS/RBDS input signal. The method also comprises preventing an error correction code (ECC) unit from modifying the filtered decode values in the RDS/RBDS output signal.

Abstract: A wireless receiver includes M antennas that each receive a wireless signal. N rake receiver modules receive the wireless signals from the M antennas and combine multipath components of the wireless signals. A summing module receives outputs of the N rake receiver modules and combines the outputs to generate an output signal. M and N are integers greater than 1.

Abstract: A system and technique for providing to flexible, programmable frequency estimators and spectrum analyzers that can operate over extremely large bandwidths and yet provide high spectral resolution are described. The acquisition time and hardware complexity of one technique scale as O(N), where N denotes the number of frequency bins acquired. Embodiments are disclosed in which architectures are implemented using exponentially-tapered transmission lines and filter cascades.

Abstract: Symbol detection and soft dempapping methods and systems are provided. Individual subset symbol detection according to an embodiment of the invention involves identifying a search subset of a transmission symbol set for a transmission symbol. For each other transmission symbol in communication signals, multiple search subsets of the transmission symbol set are identified. The multiple search subsets include respective search subsets based on each transmission symbol in either the search subset for the first identified one of the transmission symbols or each of the multiple search subsets identified for a different one of the other transmission symbols. Symbol detection errors may be detected by identifying competing symbols and computing competing distances. Soft demapping may be provided by calculating soft decision results based on detected symbols and weighting the soft decision result.

Abstract: A clock data recovery comprises a phase detector, a phase interpolator, an initial phase detector, and an initial phase decoder. The phase detector receives an incoming data stream and an interpolated clock signal and output an early/late value indicating timing relationship between the incoming data stream and the interpolated clock signal. The phase interpolator receives the early/late signal and at least one reference clock signal and generate an interpolated clock signal considering the early/late value and the at least one reference clock signal. The initial phase detector receives the incoming data stream and output a first data indicating a phase of the incoming data stream. The initial phase decoder receives data indicating a phase of the incoming data stream and select the at least one reference clock signal from a plurality of clock signals considering the data indicating a phase of the incoming data stream.

Abstract: Provided are an apparatus and method for generating a soft bit metric and a multi-level (M-ary) Quadrature Amplitude Modulation (QAM) receiving system using the same. The apparatus includes an analog to digital converter for converting an analog symbol signal of a demodulated I (Inphase) or Q (Quadrature) channel into a digital signal, a scaler for scaling the converted digital signal based on a reference value used for determining a space between symbols, a positive integer converter for calculating a positive integer of the scaled digital I or Q channel symbol signal, a sign determinator for determining a sign of the scaled digital I or Q channel symbol signal, and a bit information converter for converting the scaled digital I or Q channel symbol signal into soft bit metric information per bit on the basis of the calculated positive integer and the determined sign value.

Abstract: A signal converter. The signal converter converts an analog inphase signal and an analog quadrature phase signal into a digital baseband inphase signal and a digital baseband quadrature phase signal. The analog inphase signal and the analog quadrature phase signal are orthogonal to each other and are carried in a predetermined intermediate frequency. The digital baseband inphase signal and the digital baseband quadrature phase signal are carried in zero frequency. The signal converter comprises a signal combiner combining the analog inphase signal and the analog quadrature phase signal to obtain an analog combined signal, an analog to digital converter converting the analog combined signal to a digital combined signal, and a signal separator separating the digital combined signal to obtain the digital baseband inphase signal and the digital baseband quadrature phase signal.

Abstract: A method for multiplexing voice and data communication using a communications network is presented. In the method, at least one voice bit from a voice bit stream is retrieved, and at least one data bit from at least one data bit stream is retrieved. When the voice bit stream is not in a discontinuous transmission (DTX) period, the at least one voice bit and the at least one data bit are used to generate a modulated symbol. The method includes transmitting the modulated symbol using the communications network.

Abstract: A level of interference affecting signal components of received communication signals is estimated and used to weight the signal components. The signal components in a each of a number of groups of signal components are weighted based on respective interference estimates to thereby adjust signal components for coloured interference, which may vary significantly between different groups of signal components. Each group of signal components may include a single component or components within a relatively narrow sub-band of the communication signals, such as a coherence bandwidth of an Orthogonal Frequency Division Multiplexing (OFDM) signal.

Abstract: A method and apparatus blindly detects a received signal's modulation type characterizing an impairment component of the received signal for each postulated modulation type by determining spatial correlations between In-phase and Quadrature components of the received signal. The blind detection circuit then detects the modulation type based on the characterized impairment component. A metric generator generates a postulation metric for each postulated modulation type based on the characterized impairment component. After evaluating the postulation metrics, an evaluation circuit identifies the postulated modulation type having the best postulation metric as the modulation type of the received signal. According to an exemplary embodiment, the blind detection circuit determines a whitened noise estimate for each postulated modulation type and generates the postulation metrics based on the whitened noise estimate to reduce interference effects in the postulation metrics.

Abstract: A method and apparatus for clock recovery in synchronous digital systems. The apparatus includes a phase frequency detector, a loop filter, a compressor, and a clock generator. The phase frequency detector generates a phase error signal based on a difference between an input clock signal and an output clock signal. The loop filter multiplies the phase error signal and filters the multiplied phase error signal. The compressor divides the loop filter output. Based on the compressor output, the clock generator generates an output clock signal is provided as a feedback signal to the phase error detector. The apparatus may also include a glitch cleaner for deglitching the input clock signal.

Abstract: According to one aspect of the present invention, an apparatus is provided to enable weather band radio signals to be received and processed using a digital signal processor (DSP). The DSP can include functionality to implement both frequency modulation (FM) demodulation and weather band data demodulation, i.e., specific area encoding (SAME) demodulation. In one such embodiment, soft decision samples of a SAME message can be combined, and based on a combined result, a hard decision unit can generate a bit value of weather band data.

Abstract: Certain embodiments provide a system for recovering data from at least one signal. The system can include an analog-to-digital converter (ADC) and in-phase/quadrature (IQ) generator component that can sample a signal recovered from a communication medium to generate a first signal sample and a second signal sample. A Fast Fourier Transform (FFT) component can process the first signal sample to generate a first signal phase and process the second signal sample to generate a second signal phase. A phase difference calculation component can determine a phase difference between the first signal phase and the second signal phase, determine a bit value represented by the signal based on the phase difference, and output the bit value to an end device coupled to the phase difference calculation component.

Abstract: A carrier recovery apparatus includes a pilot strength detector, a first lock loop, a second lock loop, and a controller. The pilot strength detector determines whether a pilot strength of an input signal is greater than a threshold value to generate a control signal. The first lock loop performs a first carrier recovery on the input signal. The second lock loop performs a second carrier recovery on the input signal. The controller selectively allows the first lock loop to perform the first carrier recovery on the input signal or the second lock loop to perform the second carrier recovery on the input signal according to the control signal. The first lock loop is a pilot-based FPLL and the second locked loop is a pilot-less PLL.

Abstract: A digital direct conversion receiving apparatus, including: a phase conversion unit to down-convert a Radio Frequency (RF) signal into a plurality of sample signals, and generate a certain phase difference among the plurality of sample signals when the RF signal is down-converted; and a variable complex gain unit to remove an image component from the plurality of sample signals using the generated phase difference.

Abstract: A method and apparatus to improve adaptation speed of a digital receiver is presented. The receiver includes an equalizer to initiate adaptation to a transmission channel responsive to a first control signal, a slicer coupled to the equalizer to generate symbol decisions based at least in part on an equalized digital signal, logic to receive the symbol decisions and generate a selection signal when a lock onto a training sequence of the symbol decisions occurs, first and second phase detectors to detect phase errors of the equalized digital signal and an incoming digital signal, respectively, and a clock generator to generate a clock signal responsive to one of the first and second phase errors.

Abstract: A demodulation system for Radio Data System (RDS) signals in a receiver includes a quadrature mixer (303) configured to convert a RDS signal at an input frequency directly to a base band RDS signal, a single filter (305) configured to filter the base band RDS signal to provide a RDS signal, and a signal level detector (311) configured to provide an indication of a level of the RDS signal (313), a demodulator (315) configured to demodulate the RDS signal and provide RDS data, the RDS data corresponding to information for user consumption, where the indication is used for selectively interrupting the user consumption when the level of the RDS signal is unsatisfactory.