Abstract: A digital receiver being adapted for receiving an MSK modulated signal, comprises a digital front-end unit (10) adapted for providing samples having a phase value (?measure) of a down-mixed signal, a phase compensation unit (11) adapted for compensating the phase value (?measure) by delivering a phase offset compensated sample having a phase value (?sync), and a coherent demodulator (12) adapted for recovering information content from the phase offset compensated sample. The phase compensation unit (11) is adapted for analyzing a phase value (?sync) of the phase offset compensated sample, calculating a phase offset value (?offset) based on the phase value (?sync) of the phase offset compensated sample, and applying the phase offset value (?offset) when delivering a subsequent phase offset compensated sample.

Abstract: Provided are a device and method for performing authentication in a wireless power transfer system. Provided is an authentication method in a wireless power transfer system including receiving a first packet including indication information on whether a target device supports an authentication function from the target device; transmitting, when the target device supports an authentication function, an authentication request message to the target device; receiving an authentication response message including a certificate on wireless charging from the target device in response to the authentication request message; and confirming authentication of the target device based on the authentication response message.

Abstract: The present disclosure relates to a demodulation method, apparatus, and device. Some embodiments of the present disclosure are beneficial to improving demodulation performance.

Abstract: A sensing head (1) for a transducer for capturing rotation or linear parameters, of a rotatable or linearly movable component, in particular of a shaft (13), includes a housing (2), a first sensor unit (3) and a second sensor unit (5) arranged on the housing (2) and arranged in a circumferential direction (U) of the rotatable component offset in relation to each other. The first sensor unit has a first sensor surface (4) and the second sensor unit has a second sensor surface (6). Each of the sensor units (3, 5) can be rotated about a rotation axis (7, 30) such that the sensor surfaces (4, 6) are pivotable to each other in at least two different angular positions. The rotation axes (7, 30) of the sensor units (3, 5) are located on the sides (34, 36) of the sensor units (3, 5); forming the sensor surfaces (4, 6).

Abstract: An ion concentration measuring method and apparatus are provided. The ion concentration measuring apparatus includes an ion sensing layer in contact with a solution, a plurality of transistors having gate electrodes connected to the ion sensing layer, and a reading unit configured to change frequency information by using drain currents from the plurality of transistors and generate ion concentration information by using the frequency information.

Abstract: A modulator and demodulator pair may switch configurations without introducing errors as a result of the switch. Different configurations may, for example, correspond to different symbol rates and/or different amounts of controlled inter-symbol interference (ISI) introduced to the transmitted signal. For example, a first configuration may use be a near-zero ISI configuration (e.g., using Nyquist signaling) and a second configuration may introduce a significant (e.g., amount that would result in errors above a desired threshold if demodulation relied on symbol-by-symbol slicing) but controlled amount of ISI (e.g., using partial response or faster-than-Nyquist-rate signaling). Switching between modulator/demodulator configurations may be needed to maintain a stable link in the case of dynamic channels. At any given time, a modulator and demodulator pair may, for example, switch to a configuration that provides maximal throughput for the current channel conditions.

Abstract: An apparatus and method reduce distortion in a processed signal. The apparatus includes a first receive path, a second receive path, a summation unit, and a compensation unit. The first receive path is configured to process a received analog signal into a first digital signal. The second receive path is configured to process the received analog signal with a phase shift into a second digital signal. The summation unit is configured to sum the first and second digital signals to form a processed digital signal. The compensation unit is configured to identify a conjugate of the processed digital signal, apply a weighting factor to the conjugate of the processed digital signal to form a weighted signal, and subtract the weighted signal from the processed digital signal to reduce the distortion.

Abstract: A method for determining the voltage current phase relationship of a piezoelectric phacoemulsification handpiece generally includes the steps of obtaining an analog AC voltage signal corresponding to the operating AC voltage of a piezoelectric handpiece along with an analog AC current signal corresponding to the operating AC current of the piezoelectric handpiece. Using reference detection circuits, a digital voltage signal and a digital current signal is produced. A synchronous sample clock is taken that has a frequency that is 2N times faster than the frequency of the operating ultrasonic handpiece (i.e., driving frequency), where N is the number of digital bits allocated to the sample clock. This clock measures the time between onsets of a voltage and current cycle. This time value equates to the phase time delta between the two signals. Dividing the synchronous sample clock to obtain the driving frequency ensures the signals are synchronous.

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 two stage process is applied for recovering the modulating content from the received I-Q waveforms of a MSK modulated signal. In the first stage, at each incoming symbol the I-Q waveform segments of the input belonging to the three most recently received symbols are used in hypothesis testing. A matched filter bank produces ratings for each of the possible three symbol modulating patterns in proportion to the likelihood that the combination in question may have produced the current but by now impaired input segment. While the three symbol window slides symbol-by-symbol over the input the successive hypothesis tests are not independent as each symbol is involved in three consecutive tests. The dependence thus created lays the foundation and provides the branch metrics for applying the Viterbi algorithm for the determination of the modulating symbols in the second stage.

Abstract: Aspects of a method and system for wireless local area network (WLAN) phase shifter training are presented. Aspect of the system may enable a receiving station, at which is located a plurality of receiving antennas, to estimate the relative phase at which each of the receiving antennas receives signals from a transmitting station. This process may be referred to as phase shifter training. After determining the relative phase for each of the receiving antennas, the receiving station may process received signals by phase shifting the signals received via each of the receiving antennas in accordance with the relative phase shifts determined during the phase shifter training process. Signals received via a selected one of the receiving antennas may be unshifted. The processed signals may be combined to generate a diversity reception signal.

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: An apparatus and a method that provide traffic information using radio traffic broadcasting that provides corresponding traffic information to a driver when the driver requests the corresponding traffic information, without requiring a separate digital modulation module, by recording radio traffic broadcasting in a streaming scheme. In addition, corresponding traffic broadcasting is extracted and stored in a file form when a street name, a land mark, a location name, or the like, on a destination path set by the driver is recognized as an audio in the recorded radio traffic broadcasting.

Abstract: A method for encoder frequency-shift compensation includes determining frequency values of an input encoder signal, determining repeatable frequency-shifts of the frequency values and generating a frequency-shift compensated clock using the repeatable frequency-shifts. A frequency-shift compensated clock includes a synthesizer configured to generate a frequency-shift compensated clock signal using repeatable frequency shifts and encoder clock 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 wireless communications device includes a receiver, and a demodulator coupled downstream from the receiver and configured to use a continuous phase modulation (CPM) waveform to non-coherently demodulate a received signal. The demodulator is configured to generate waveform banks, each waveform bank having a respective different frequency offset associated therewith, determine a correlation output metric for each waveform bank, select a waveform bank for demodulating the received signal based upon the correlation output metrics of the waveform banks, and demodulate the received signal using the selected waveform bank and the associated frequency offset.

Abstract: A method includes modulating, at a first wireless device, a first signal based on a Gaussian minimum shift keying (GMSK) modulation scheme to generate a modulated signal. The method also includes amplifying, at the first wireless device, the modulated signal using a nonlinear power amplifier to generate an output signal. The method further includes transmitting, from the first wireless device to a second wireless device, an output signal generated based on the modulated signal via a wireless local area network (WLAN) that is compliant with an Institute of Electrical and Electronics Engineer (IEEE) 802.11ah specification.

Abstract: Carrier frequency offset (CFO) between a transmitter and receiver signaling at 2 Mbps data rate with a 11110000 pattern as the preamble period is corrected within one preamble time period using free-running coarse and fine carrier frequency offset estimations. Two estimates for the CFO are computed, coarse and fine. The fine one is computationally accurate but may not be correct because of a potential wrap at ±180° in the computation. The coarse one is not accurate but delivers the approximate CFO value without wrap over. The comparison between the coarse and fine estimates thus may be used to detect a wrap over in the fine estimate and modify the fine estimate accordingly. Thereafter the compensated fine CFO estimation is used for carrier frequency offset (CFO) compensation.

Abstract: Aspects of a method and system for wireless local area network (WLAN) phase shifter training are presented. Aspect of the system may enable a receiving station, at which is located a plurality of receiving antennas, to estimate the relative phase at which each of the receiving antennas receives signals from a transmitting station. This process may be referred to as phase shifter training. After determining the relative phase for each of the receiving antennas, the receiving station may process received signals by phase shifting the signals received via each of the receiving antennas in accordance with the relative phase shifts determined during the phase shifter training process. Signals received via a selected one of the receiving antennas may be unshifted. The processed signals may be combined to generate a diversity reception signal.

Abstract: The embodiments disclose a method for encoder frequency-shift compensation, including, determining frequency values of an input encoder signal, analyzing an encoder index clock signal and the input encoder signal to determine values of frequency-shifts and compensating for the values of the frequency-shifts to generate a frequency-shift compensated clock.

Abstract: A technique for receiving spread spectrum GMSK signals that demodulates Gaussian Minimum Shift Keying transmissions involving a sequence of data symbols, a spread spectrum code comprising a sequence of spread spectrum chips, a sequence of pre-modulation chips combining the sequence of data symbols with the spread spectrum chips, wherein for each data symbol, at least one of the pre-modulation chips is generated by taking into account at least the data symbol and at least one of the spread spectrum chips.

Abstract: Systems (600) and methods (100) for demodulating a Gaussian Filtered Minimum Shift Keyed (GMSK) signal. The GMSK signal is defined in a transmitted symbol domain where each symbol is given by a product of a current data bit and a previous data bit. The GMSK signal is converted from the transmitted symbol domain to a data symbol domain. The conversion is achieved by approximating filtered complex output signals that would be produced by matched filters having filter shapes corresponding to pulses used in terms of a Laurent expansion. Subsequent to the convention of the GMSK signal, a trellis equalization of the GMSK signal is performed exclusively in the data symbol domain based on the terms of the Laurent expansion.

Abstract: A transmission device (10) includes: a series/parallel converter (11); an MSK modulator (31) for modulating a signal on a channel basis; a D/A converter (13); a frequency converter (14a) for conversion into different carrier frequencies; a synchronization circuit (32); an amplifier (15); a multiplexer (16) for multiplexing amplification signals; and an antenna (19).

Abstract: Radio equipment (RE) is shared so as to use a plurality of types of radio signals, and data (IQ data) of the plurality of types of radio signals and monitoring control data are variably arranged in a frame for transmitting and receiving data between the RE and radio equipment controls (RECs). A plurality of types of data are simultaneously transmitted and received by one communication link between the RE and the RECs.

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: The present invention provides methods and systems for allowing a receiver in a (wireless) communication system to synchronize its timing and frequency subsystems in accordance with a received signal. In accordance with one aspect, a method is provided in which a relative time of arrival of sync values provided in a received signal are determined and used to align the receiver's reference signal(s) accordingly. Other aspects of the invention will become apparent from the detailed description of exemplary embodiments that follows.

Abstract: A technique for low-complexity high-performance coherent demodulation of GFSK signals involves utilizing a novel phase and frequency tracking mechanism coupled with a trellis search technique to track signal memory in the demodulation process. A method according to the technique may include modeling modulation based upon a trellis. The method may further include estimating unknown parameters, selecting a maximum likelihood path through the trellis, and mapping the maximum likelihood path to an output bit sequence. The technique is also applicable to DSPK and other applicable known or convenient protocols.

Abstract: A method, a hardware product, and a computer program product for performing high data rate wireless transmission and reception. Minimum shift-keyed (MSK) data is transmitted by multiplexing a first MSK data stream and a second MSK data stream wherein the first MSK data stream is substantially 90-degree phase-shifted with respect to the second MSK data stream. The transmitted MSK data is received by performing phase recovery and demodulation using an FM discriminator having a demodulation circuit for implementing a 45-degree phase shift prior to demodulation.

Abstract: A method and architecture for pulse shaping are provided. The architecture includes a pulse shaping filter having a plurality of memory elements and a plurality of taps connected to the plurality of memory elements wherein a total number of the plurality of taps is independent of a sampling rate. The pulse shaping filter further includes a selector configured to select outputs from the plurality of taps to define a pulse shaped output.

Abstract: Method in a diversity antenna GMSK receiver of determining interference canceling equalizers and corresponding equalizers are described. The method includes providing a plurality of GMSK received signals; de-rotating and splitting each of the plurality of received signals into in phase and quadrature parts to provide a multiplicity of real valued branches; calculating linear equalizers for each of a multiplicity of subsets of the multiplicity of real valued branches; and providing an interference canceling equalizer for each of the multiplicity of real valued branches, each interference canceling equalizer corresponding to a weighted combination of the linear equalizers. A corresponding equalizer includes eight linear equalizers processing four branch signals corresponding to real (I) and quadrature (Q) parts of a GMSK diversity signal from two antennas.

Abstract: A GMSK receiver with interference cancellation includes a linear equalizer configured to be coupled to a received signal from a first antenna and to provide first soft bits, an adaptive estimator, e.g., adaptive MLSE coupled to the first soft bits and configured to provide second soft bits; a quality assessor coupled to the first soft bits and configured to provide a quality indication; and a switching function coupled to the linear equalizer and the adaptive MLSE and controlled in accordance with the quality indication to provide output soft bits corresponding to at least one of the first soft bits and the second soft bits. The GMSK receiver can be extended to multiple antennas and corresponding methods for interference cancellation in a GMSK signal are discussed.

Abstract: An algorithm for a non-redundant multi-error correcting binary differential demodulator simplifies error detection and reduces memory requirements in circuits embodying the same. The demodulator includes a differential detectors (DD) module, an error signal generator (ESG) module, and an error detection-and-correction (EDAC) module. The DD module receives modulated binary input at each of (k+1) differential detectors, each producing (k+1) outputs. The ESG module combines the (k+1)2 output signals with k corrected feedback signals to derive syndromes orthogonal to an erroneous bit to be corrected and generates 2k error signals from the syndromes. The EDAC module generates a correction factor from the 2k error signals and combines the factor with the output of the first order detector delayed by k bits to correct an erroneous bit. The k corrected feedback signals may be derived by successively delaying the corrected erroneous bit.

Abstract: A data modular based on Gaussian minimum shift keying (GMSK) modulation and a data transmitter including the same in which the data modulator includes a read-only memory (ROM) table storing GMSK modulation data with respect to information bits; a low-pass filter filtering first GMSK modulation data, which is output from the ROM table based on a predetermined input bitstream, and outputting second GMSK modulation data; and a multiplexer selecting and outputting the first GMSK modulation data or the second GMSK modulation data based on a predetermined control signal. The data modulator selectively filters a GMSK modulation signal according to a channel state, thereby effectively controlling trade-off between inter-symbol interference and adjacent channel interference according the channel state.

Abstract: An OFDM receiver includes a demodulator unit being coupled to a received signal for demodulating both an in-phase (I) component and a quadrature-phase (Q) component of the received signal; a serial to parallel unit for converting the output of the demodulator to a plurality of parallel paths, each path corresponding to a particular tone and having a plurality of time-domain samples; a fast Fourier transform circuit for generating frequency domain samples from the time-domain samples; and a equalization and I-Q mismatch correction circuit being coupled to the fast Fourier transform circuit for performing both frequency domain equalization and I-Q mismatch correction on at least one frequency domain sample being output by the fast Fourier transform circuit.

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

Abstract: The modulator according to the invention is based on the modulation of a PLL, with the bandwidth of the PLL being variable. The modulator also has a means (14, 15) for determination of a signal (?r(kTs); FDEV) which is characteristic of the modulation shift of the modulated signal. Furthermore, the modulator contains a comparison means (16) for comparison of this signal with a signal (?(kTs+?); FDEVNOM) which is characteristic of the nominal modulation shift, as well as a means (18) for variation of the bandwidth as a function of the output signal from the comparison means (16).

Abstract: A non-redundant differential MSK demodulator with double-error correction capability includes a differential detection stage, an error signal generator stage, and an error detection-and-correction stage. Differential detectors receive modulated MSK input. The error signal generator converts outputs from the differential detectors into orthogonal error signals. The error detection-and-correction stage compares an algebraic sum of the error signals to a threshold value and outputs a correction value based thereon. The correction value is added to output from the differential detection stage to produce demodulated MSK output.

Abstract: A wireless communication device processes N Radio Frequency (RF) bursts contained within N slots of a digital communications time divided frame, wherein N is a positive integer greater than one. The wireless communication device includes an RF front end, a baseband processor, and an equalizer module. The RF front end is operable to receive the plurality of received RF bursts and to convert the RF bursts to corresponding baseband signals. The baseband processor is operable to receive the baseband signals, to pre-equalization process the baseband signals to produce processed baseband signals, and to post-equalization process soft decisions. The equalizer is operable to equalize the processed baseband signals to produce the soft decisions. These RF bursts may be contained in adjacent slots or, in non-adjacent slots, or in a combination of adjacent slots and non-adjacent slots.

Abstract: A GMSK modulator includes a dual-port memory, an address generator and a signal provider, where the dual-port memory respectively outputs in-phase and quadrature phase waveform data to first and second ports in response to in-phase and quadrature phase waveform address signals, the address generator generates the in-phase and quadrature phase waveform address signals based on a differential encoded bit stream, the signal provider selects one of the in-phase and the quadrature phase waveform data in response to the differential encoded bit stream, and outputs continuous GMSK in-phase and quadrature phase channel signals, and the redundancy of the memory that stores the GMSK in-phase and quadrature phase waveform data may be reduced using the dual-port memory so that the size of the memory may be reduced.

Abstract: A receiver for receives transmitted signals and each transmitted signal contains at least two known portions which are spaced from one another in the signal and at least one other portion. The receiver comprises channel estimation means for estimating a channel based on at least one of the known portions, and means for using the channel estimate and at least two of the known portions to determine a characteristic of the channel.

Abstract: Prefilters for a receiver with multiple input branches are trained in the frequency domain. The frequency response B of a conditioned channel is determined without reference to the prefilters, and the frequency response W of the prefilters is computed from the frequency response B of the conditioned channel. The prefilters suppress interference.

Abstract: A system communicates data and includes an encoder for encoding communications data with a forward error correction code. A data randomizer randomizes the communications data with a random bit sequence and a combining circuit combines the communications data with known symbols into frames. A modulator maps the communications data into minimum shift keying or Gaussian minimum shift keying (MSK or GMSK) symbols based on a specific mapping algorithm to form a communications signal having an MSK or GMSK waveform over which the communications data can be transmitted.

Abstract: The disclosed invention provides a method, a system and a computer program product for the maximum likelihood sequence estimation of transmitted MSK symbols. The disclosed invention provides a set of optimizations of the Viterbi algorithm for equalizing MSK symbols. The transmitted MSK symbols are alternately real and imaginary. Therefore, based on whether the transmitted MSK symbol is real or imaginary, the disclosed invention divides the set of Viterbi states into two sets of states. The disclosed invention obtains the surviving path only for the first set of states at stages corresponding to real transmitted symbols. A real hypothesis is used to obtain the surviving paths for the first set of states. The disclosed invention also obtains the surviving path only for the second set of states at stages corresponding to imaginary transmitted symbols. An imaginary hypothesis is used to obtain the surviving paths of the second set of states.

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: Transference of signaling frames on GERAN (GSM/EDGE radio Access Network) half rate channels utilizing a modulation scheme carrying n bits in one symbol. In order to be able to utilize the existing channel coding developed for channels with different modulations and to avoid high rate convolutional and block codes, the AMR signaling frame to be transferred is coded using a coding procedure defined for a GSM half rate channel utilizing a GMSK modulation scheme, the coding procedure outputting a coded output stream. In response to said coding, each bit of the coded output stream is repeated n times, whereby a repeated bit stream is obtained, and symbols to be transmitted are formed from the repeated bit stream.

Abstract: A non-redundant differential MSK demodulator with double-error correction capability includes a differential detection stage, an error signal generator stage, and an error detection-and-correction stage. Differential detectors receive modulated MSK input. The error signal generator converts outputs from the differential detectors into orthogonal error signals. The error detection-and-correction stage compares an algebraic sum of the error signals to a threshold value and outputs a correction value based thereon. The correction value is added to output from the differential detection stage to produce demodulated MSK output.

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: This disclosure is directed to digitally implemented GMSK modulation techniques. The digital GMSK modulation techniques make use of a lookup table (LUT) and mapping logic to digitally generate GMSK waveforms. The mapping logic can significantly reduce the size of the LUT, and thereby reduce memory requirements needed for effective digitally implemented GMSK modulation.

Abstract: A method for multi-user detection includes receiving a complex input signal due to a superposition of waveforms encoding symbols in a real-valued constellation, which are transmitted respectively by a plurality of transmitters in a common frequency band. The complex input signal is sampled at sampling intervals over the duration of an observation period to provide a sequence of complex samples. The sequence of complex samples is processed to determine soft decision values corresponding to the symbols transmitted by the plurality of the transmitters in the observation period, while constraining the soft decision values to be real values. The soft decision values are then projected onto the constellation to estimate the transmitted symbols.

Abstract: A communications channel detector which determines the availability of a desired type of communications channel in a communication system having at least one communications channel, the communications channels including data streams comprising a number of data symbols. The channel detector includes a phase detector, a phase comparator coupled to the phase detector, and a phase correlator coupled to the phase comparator. The phase detector is configured to provide a plurality of phase measurements for at least two consecutive data symbols comprising a selected one of the communications channels. The phase comparator is configured to determine the phase differences between the obtained phase measurements. The phase correlator is configured to determine the whether or not the determined phase differences exhibit a predetermined phase difference profile.