Abstract: Symbol timing acquisition is described for a wireless broadband signal received at a user terminal from a gateway via a satellite. In-phase and quadrature channels of the wireless signal may each be sampled at a rate of one sample per symbol. The samples may be interpolated to generate an early interpolation and a late interpolation for each of the samples. A difference measurement is obtained between the early interpolation and the late interpolation for a set of the samples. A number of the difference measurements may be averaged, and symbol timing may be modified based on the average. This process may be continued on an iterative basis to acquire symbol timing.

Abstract: A wireless sensor with fast correlator to detect a known pattern. The wireless sensor with fast correlator comprises a wireless receiver with bank of detectors and bank of correlators, a receive signal strength measurement circuit, and a control processor with timing counter. The fast correlator comprises of a shift register, an array of ENXOs gates, an array of AND gates and Delays and a final AND gate. The control processor utilizes the received information, received signal strength and timing information to estimate and calculate various environmental parameters which can be used to activate different devices.

Abstract: A receiver receives, using a plurality of antennas, a multiplexed signal that includes (i) a first OFDM modulation signal with a subcarrier carrying a symbol including multiplex information and a subcarrier carrying a pilot symbol and a subcarrier carrying a data symbol and (ii) a second OFDM modulation signal with a subcarrier carrying a symbol including multiplex information and a subcarrier carrying the pilot symbol and a subcarrier carrying the data symbol. A decoder uses the symbol including multiplex information and decodes the data symbol.

Abstract: The present invention relates to a combiner, channel identifier, Orthogonal Frequency Division Multiplexing OFDM receiver and method for optimizing use of channel state information of a received signal. The method comprises analyzing a received signal in a time domain and extracting from the received signal characteristics of a communication channel. The method furthermore comprises determining a dynamic indicator of channel station information accuracy based on the characteristics of the received signal. Additionally, the method comprises applying a weight to the channel state information according to the dynamic indicator.

Abstract: In a wireless communication system where communication devices exchange information utilizing physical layer (PHY) data units that conform to a first format, where the first format includes a short training field (STF) that includes exactly N repetitions of a spreading sequence, a method for generating a PHY data unit that conforms to a second format, where the second format has a longer STF than the first format, includes generating an STF of the PHY data unit that includes M instances of the spreading sequence, where M is greater than N, and generating a channel estimation field (CEF).

Abstract: A receiver circuit includes an estimation unit configured to estimate a noise power of a transmission channel, a calculation unit configured to calculate a decision variable based on the noise power, and a decision unit configured to make a ternary decision based on the decision variable.

Abstract: Provided is a method of scanning for broadcast services in a broadcast signal to generate a broadcast service list for use with a digital radio receiver system, and the digital radio receiver system used for scanning for broadcast services to generate a broadcast service list. The system utilises spectrum awareness data, which includes data defining one or more frequencies at which broadcast services may be receivable, in order to reduce the number of frequencies to scan such that the overall scan time may be reduced. The data in the spectrum awareness data is a filtered subset of the plurality of frequencies at which the broadcast services may be received, which allows the controller of a digital radio receiver to tune a tuner to only the frequencies that are likely to contain a broadcast service when generating or updating a broadcast service list.

Abstract: A device is provided for use of an antennal base formed of two antennas which pick up the emissions present and produce two radioelectric signals S1 and S2. These two signals are used to produce at least one intermediate-frequency signal Fl by demodulation of one of the two signals by the other (autotransposition). The demodulation is carried out by firstly transposing one of the signals, S1 for example, around a given frequency F1, the signal S2 being preserved around its initial central frequency F0. Thus, whatever the central frequency F0 of the emission picked up by the antennas, the demodulation produces a signal of central frequency F1, thereafter demodulated into a given intermediate frequency Fl by a local oscillator of constant frequency F2=F1+Fl. The device is applied to the production of a device for detecting emissions and for characterizing the emissions picked up.

Abstract: An approach is provided for correlation of a signal over time and frequency. The signal is correlated with a bit sequence over time instances and certain frequency offsets, wherein sub-segments of the signal are correlated with sub-segments of the bit sequence to generate a correlation factor associated with each signal sub-segment. The correlation factors are coherently combined to generate a final correlation factor, wherein a respective phase shift (for each frequency offset) is applied to each correlation factor to generate a set of frequency adjusted correlation factors, and the frequency adjusted correlation factors of a respective set are combined to generate the final correlation factor over the signal sub-segments, resulting in the matrix of final correlation factors over time and frequency. A signal parameter estimation is performed, based on the matrix of final correlation factors, to determine a highest correlation value for the signal over the frequency offsets.

Abstract: The present invention provides a method for coarse frequency synchronization in an OFDM receiver. Even if the maximum variation of crystal oscillator (X-TAL) frequency disturbance is maximized and most of the variation in crystal oscillator (X-TAL) frequency disturbance is vary small, the estimation or search method of the present invention is capable of rapidly and effectively terminating the estimation of the integral multiple frequency offset (IFO). The integral multiple frequency offset (IFO) candidate is ascendingly increased and descendingly reduced at one value interval. In the estimation IFO, the correlation peak value in the intermediate status is compared to the thresholds, the coarse frequency synchronization (CFS) acquisition directly is ended and ensured when the correlation peak value is greater than the threshold, and a confidence check is not performed when correlation peak value is less than the threshold for considerably reducing the acquisition time of the CFS.

Abstract: A synchronization system for initial setup of phases of local oscillators in a wireless receiver of a communication system characterized by transmission of data packets having a predetermined preamble consisting of M identical sections of L symbols followed by a single section of the same kind, multiplied by ?1, and wherein the wireless receiver is operative to perform decimation in an RF demodulator. The synchronization system includes a twofold correlator, an accumulator, a multiplier, a threshold comparator, a carrier phase former and a clock phase former, and operates at a decimated symbols frequency, and performs not only preamble detection, but also symbols clock phase detection together with carrier phase detection, while enabling the theoretically possible noise immunity.

Abstract: A system for reduced pair Ethernet transmission. The system includes an interleaver that is operable to receive sets of four code symbols from a physical channel sub-layer (PCS) encoder, wherein each code symbol of each set of four code symbols is associated with one of four channels, and interleave the sets of four code symbols to generate a plurality of interleaved code symbols. The system further includes a serializer that is operable to serialize the plurality of interleaved code symbols to generate a plurality of interleaved and serialized code symbols. The system further includes a transmitter that is operable to transmit the plurality of interleaved and serialized code symbols over an Ethernet medium comprising a single twisted pair of wires.

Abstract: An OFDM generation apparatus and methods for generating OFDM transmission signals from OFDM symbols, each including a plurality of OFDM subcarriers, for transmission in a multi-carrier data transmission system, is provided. The provided apparatus and method may use a selected mixing frequency for mixing complex time-domain samples of OFDM symbols from a baseband frequency up to a passband frequency to obtain OFDM transmission signals, wherein the mixing frequency is selected such that common phase rotations of the OFDM subcarriers of OFDM symbols with respect to adjacent OFDM symbols of the OFDM transmission signals are avoided or compensated after the mixing. Additional apparatuses and methods for avoidance or compensation of such common phase rotations are also provided.

Abstract: A method is provided for improving synchronization and information transmission in a communication system, including: generating a signal with a centrally symmetric part s(k) exploitable for synchronization; and sending the signal over a communication channel. The signal is based on a uniquely identifiable sequence c(l) from a set of sequences exploitable for information transmission. The centrally symmetric part s(k) is centrally symmetric in the shape of absolute value thereof. The centrally symmetric part s(k) is of arbitrary length N.

Abstract: A method is provided for synchronization in a communication system. A receiver receives and processes a signal with a centrally symmetric part s(k) exploitable for synchronization. The signal is based on a uniquely identifiable sequence c(l) from a set of sequences exploitable for information transmission. The centrally symmetric part s(k) is centrally symmetric in the shape of absolute value thereof. The centrally symmetric part s(k) is of arbitrary length N, and the sequence c(l) is a Zadoff-Chu sequence.

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: Methods and apparatuses for OFDM spectrum sensing are provided. The proposed spectrum sensing algorithms are based on Time-Domain Symbol Cross-Correlation (TDSC-MRC and TDSC-NP methods) and can be applied to all existing wireless OFDM systems. The statistical behaviors of the TDSC-based spectrum sensors are explicitly analyzed. In addition, the spectrum sensing method employing the Cyclic Prefix of the OFDM modulated signals (CP method) is described for comparison purposes. The DVB-T Standard is adopted as an application example to illustrate the proposed spectrum sensing algorithms. Simulation results show that the TDSC-MRC method outperforms the CP method for all values of CP ratio considered. The TDSC methods have the advantage that the detection performances are the same for different CP ratios, while the detection performance of the CP method degrades dramatically when the CP ratio becomes small.

Abstract: A method and a device for detection in cell random access are provided. The method includes: extending an original format used for a random access procedure to change a CP range defined by the original format; in the process of extracting a time-domain signal of a random access channel, extracting and splitting input data into time-domain antenna data in the original format and time-domain antenna data in an enhanced format, and performing signal extraction processing on the time-domain antenna data in the original format and the time-domain antenna data in the enhanced format respectively; and in the process of detection, detecting the time-domain antenna data in the original format and the time-domain antenna data in the enhanced format after the signal extraction processing to obtain detection information. The method can improve the performance of a BS and reduce the network construction costs without affecting an MS.

Abstract: A tunable filter reduces the total number of filters used in TDD (Time-Division Duplex) communication circuitry. The communication circuitry may include a tunable filter and a first switch associated with the tunable filter. The tunable filter may include a tuning component and a filtering component. The tuning component may be located with the first switch on a first die. The filtering component may be located in a laminate underneath the first switch. Power amplifiers for amplifying transmission signals may be located on a second die, and the second die may be located on the laminate.

Abstract: A method of performing receive antenna selection is presented. The method executes a determination operation for a set of receive antennas, determines a maximum result of the determination operation for two of the antennas, eliminates one of the two antennas from the set of antennas, and repeats the determination and elimination process until only a predetermined number of antennas remain in the set. The signals from these remaining antennas are then processed. The present invention reduces receiver complexity and cost.

Abstract: The present disclosure provides a frequency offset compensation technique for use by a multi-carrier receiver. Compared with legacy receiver designs, the technique introduces a new function which correlates various frequency offsets of the different carriers involved in multi-carrier signal transmission and reception. This new function can be coupled with an Automatic Frequency Control (AFC) function which can then utilize the correlation information provided by the new function to achieve significantly better frequency error/offset estimation when the carriers are correlated.

Abstract: A digital front-end circuit is disclosed. In one aspect, the circuit includes a filtering block for filtering received data. The filtering block has a first filter branch for filtering the received data in a first frequency band and a second filter branch for filtering the received data in a selected second frequency band. The second filter branch is in parallel with the first filter branch, is programmable and includes a block for resampling the received data. The front-end circuit also includes a circuit for performing synchronization and spectrum sensing on the received data, which is in connection with the output of the filtering block. The front-end circuit also includes a controller block for controlling the filtering block and the synchronization circuit.

Abstract: Signal power of a received signal, which has a plurality of preamble sequences associated with sub-carrier signals received from a plurality of sub-carriers, in a cellular Orthogonal Frequency Division Multiplexing system may be estimated by estimating as power for at least one preamble sequence of a signal received at a selected receive antenna. The preamble sequence is associated with a base station and a set of sub-carriers. A differential received signal developed for one of the set of sub-carriers is correlated with a normalized differential transmit signal for the preamble sequence, and the estimate of the power for the at least one preamble sequence is extracted based on the correlation.

Abstract: There is provided a method of method of estimating a quality of a signal, the method in a first device comprising measuring a signal transmitted from a second device to a third device; determining a value of a metric from an autocorrelation function of the measured signal; and determining an estimate of the quality of the signal from the determined metric.

Abstract: The method of performing structure-based Bayesian sparse signal reconstruction is a Bayesian approach to sparse signal recovery that has relatively low complexity and makes a collective use of: a priori statistical properties of the signal and noise; sparsity information; and the rich structure of the sensing matrix ?. The method is used with both Gaussian and non-Gaussian (or unknown) priors, and performance measures of the ultimate estimate outputs are easily calculated.

Abstract: A computational processor uses a binary signal, being a set of 1- or 0-valued elements of a same number as a number of elements in an input signal, to generate computational data whose elements are exclusive OR values between each element of the input signal and a corresponding element in the binary signal at a same position. The modulator 13 modulates the input signal and the computational data according to a primary modulation scheme, and generates primary-modulated signals. An IFFT calculator applies an inverse fast Fourier transformation to the primary-modulated signals to generate inverse transformation data. A transmitter generates a baseband signal based on generated inverse transformation data whose peak-to-average power ratio matches a standard, and generates and transmits a transmission signal from the baseband signal and data specifying computations conducted to generate the inverse transformation data that matches the standard.

Abstract: A receiver may be operable to receive a QAM-based, inter-symbol correlated (ISC) signal having pilot overhead of 5% at a signal-to-noise ratio (SNR). The receiver may be operable to process the QAM-based, ISC signal to output information at a particular rate with a symbol error rate lower than or equal to 1e-2. The first SNR may be at least 3 dB below a SNR required to achieve the same particular information rate and the same symbol error rate while processing a signal having zero inter-symbol interference.

Abstract: A preamble detector has a correlator outputting for every sample position of the preamble part of an incoming sampled signal stream a score and associated class value; and a multiple cluster unit receiving the class and score output values from the correlator, wherein a first cluster receives output values from the correlator and the following clusters are coupled in series such that each cluster receives output values from the correlator and a preceding cluster and wherein the output values of the correlator and a cluster are processed such that an n-th cluster of the multiple cluster unit, with n>1, accumulates the highest score values of n score values with matching class values.

Abstract: The present invention relates a method, apparatus, receiver, computer program for joint detection. In the method, it is firstly determined if whether a number of original active codes is beyond a predefined threshold or not, and when the number of the original active codes is beyond the predefined threshold and a strong interference code exists in the active codes corresponding to intra-frequency adjacent cells, it is to apply an interference cancellation to a receive signal, cancel MAI caused by a strong interference signal corresponding to the strong interference code, and perform a joint detection by utilizing a matched filtering result of a remaining signal after the interference cancellation for the joint detection. According to at least one embodiment of the present invention, when there is large interference in the intra-frequency adjacent cells and the number of the active codes is beyond a maximum threshold, the joint detection performance is improved.

Abstract: A method of communication parameter detection for detecting a temporal length of a guard interval of cyclic messages in a communication is provided. The method includes: searching peaks of an autocorrelation signal in the communication signal, and providing a peak for each cyclic message; sorting a time difference between two consecutive peaks to one of bins of a histogram, and determining the temporal length of the guard interval according to a result of the histogram; while a peak is found, providing a signal average according to an average of the autocorrelation signal over an average calculating period, comparing whether a ratio of the peak to the signal average is greater than a threshold, and accordingly detecting whether the communication signal carries valid information.

Abstract: According to embodiments herein an ambiguity problem when compensating for frequency offset may be solved by compensating a received reference symbol according to two different frequency offset hypotheses; the estimated frequency offset and the a mirrored version of the same. Then by comparing the compensated reference symbol of the different frequency hypotheses with a target reference symbol, which is known at the receiver node 12, the frequency offset hypothesis which is most likely is used to compensate a received data symbol.

Abstract: The present invention relates to a method for generating impairment covariances for equalization in a receiver of a wireless communication system, as well as an covariance estimator, a receiver and a wireless communication system associated therewith, where the receiver is equipped with multiple antennas, and an impairment covariance matrix is used to calculate equalization weighting vector for signals transmitted by a transmitter, the method comprising the steps of: calculating a raw impairment covariance estimate between a first antenna and a second antenna of the multiple antennas on each of subcarriers allocated to the transmitter in frequency domain, transforming the raw impairment covariance estimates into time domain, masking the transformed impairment covariance estimates by a triangle window with a width defined by a maximum delay spread, determining a threshold based on the transformed impairment covariance estimates for the subcarriers and thresholding the masked impairment covariance estimates wit

Abstract: A mobile device that operates in a wireless communication network is disclosed. The mobile device includes a transceiver that uses a first wireless communication technology, which can be Long Term Evolution (LTE) technology. The mobile device also includes a modem that coupled to the transceiver through a standard interface and uses a second wireless communication technology, which can be CDMA. The modem processes the received signal from the transceiver and processes a transmit signal for the transceiver. A first receiver first processing circuit has a matching filter to compensate for and resampling the received signal from the receiver so that that the received signal from the transceiver is compatible with the modem. A transmitter processing has a filter for resampling and adjusting a processed transmit signal for the transmitter.

Abstract: Disclosed are various embodiments for reducing the amount of electromagnetic interference (EMI) that may be present in a received signal. A frequency component for the received component is generated. An EMI frequency, an EMI phase, and an EMI amplitude present in the frequency component are tracked. Cancelling data is generated responsive to the EMI frequency, the EMI phase, and the EMI amplitude present in the frequency component.

Abstract: A method is for decoding a pulse signal modulated through a transmitted reference modulation scheme. The modulated pulse signal may include, repetitively, a reference pulse followed by an information pulse delayed with a delay. The method may include subtracting or adding from the modulated pulse signal, a version of the modulated pulse signal delayed with the delay for obtaining a processed signal, and performing a non-coherent detection on the processed signal.

Abstract: The present invention discloses a method and a device for detecting a primary synchronization signal and generating a sequence in a LTE system, so as to solve the problem that the overhead for 3GPP LTE system to store a local primary synchronization sequence is too much during the initial cell search process. The method for detecting a primary synchronization signal includes: directly generating a local primary synchronization signal sequence with equal amplitude in the time domain as a matched filter; performing a front-end processing for a received signal; performing the matched filtering between the received signal after the front-end processing and the local primary synchronization signal sequence; judging the output amplitude of the signal sequence obtained after the matched filtering; and then obtaining a judgment result of the local primary synchronization signal sequence.

Abstract: An approach is provided to compensate for inter-carrier interference caused by phase noise in a transmitted or received signal. The approach involves causing an estimation of one or more phase noise spectrum taps that cause inter-carrier interference in a received signal. The approach also involves causing an approximation of an instantaneous phase noise spectrum by a low order finite impulse response filter based on the estimated one or more phase noise spectrum taps. The approach additionally involves determining a de-convolution filter having two or more filter coefficients for one or more orthogonal frequency-division multiplexing symbols associated with the received signal. The approach further involves causing the de-convolution filter to be matched to the approximated instantaneous phase noise spectrum.

Abstract: A transmitter, receiver, and method for channel estimation for a Multiple-Input Multiple-Output (MIMO) communication system in which the transmitter includes a multiplicity of transmit antennas spaced such that spacing between adjacent antennas provides a spatial correlation coefficient greater than a threshold level. The transmitter selects a subset of the multiplicity of transmit antennas for transmitting the pilot reference signals. The pilot reference signals are transmitted only from the selected subset of transmit antennas to the receiver. The receiver includes a channel estimator configured to derive a channel estimation for all of the multiplicity of transmit antennas using the received pilot reference signals and known or estimated spatial correlation among the multiplicity of transmit antennas.

Abstract: A method for signal processing includes accepting an analog signal, which consists of a sequence of pulses confined to a finite time interval. The analog signal is sampled at a sampling rate that is lower than a Nyquist rate of the analog signal and with samples taken at sample times that are independent of respective pulse shapes of the pulses and respective time positions of the pulses in the time interval. The sampled analog signal is processed.

Abstract: A receiving apparatus includes a correlation operation unit and a determination unit. The correlation operation unit is configured to perform a correlation operation with a known signal on a received signal including the known signal in a predetermined interval. The determination unit is configured to determine whether or not a correlation peak interval detected by the correlation operation unit deviates from the predetermined interval.

Abstract: A circuit can include an input section configured to store a data signal in response to phase shifted clocks to generate a plurality of sample values; an output section configured to store one of the sample values; and a logic section configured to selectively output one of the sample values to the output section in response to the sample values and a previous sampled value stored in the output section.

Abstract: A receiver and a method for equalizing signals, the method includes: receiving input signals; sampling the input signals to provide oversampled samples; processing the oversampled samples to provide symbol spaced samples and to provide fractionally spaced samples that represent the oversampled samples; calculating taps of a fractionally spaced equalizer based on the symbol spaced samples; feeding the taps to the fractionally spaced equalizer; and filtering the fractionally spaced samples by the fractionally spaced equalizer to provide equalized samples.

Abstract: According to one or more embodiments, multiple transmitters may simultaneously transmit orthogonal acquisition sequences with certain frequencies zeroed out, such that receivers receiving a signal (waveform) may separate the signal into the orthogonal sequences based on which frequencies are zeroed out to perform acquisition processes. For example, each transmitter may simultaneously transmit an orthogonal acquisition sequence with certain tones zeroed out depending upon which transmitter transmits the symbol. A particular receiver may then receive a signal, and filter it to produce a plurality of filtered signals that distinguish orthogonal acquisition sequence symbols based on which tones are zeroed out within the symbols.

Abstract: The present disclosure provides for a method and apparatus for efficient cross-correlation between a reference sequence and a received sequence in a wireless communication system. The reference sequence includes a concatenation of sign-adjusted sub-sequences, the sign adjustments determined by a first sign sequence of a set of sign sequences. For example, the reference sequence may be an alternating concatenation of sign-adjusted Golay complementary pair sub-sequences. The received sequence is shifted to provide a plurality of time shifted sequences that are then cross-correlated with the sub-sequences to form a set of partial cross-correlations. The partial cross-correlations are sign-adjusted using the first sign sequence and combined to produce the cross-correlation between the reference sequence and the received sequence. The cross-correlations so produced may be used for channel signature (e.g. PHY-type) identification and/or channel impulse response estimation.

Abstract: Method and associated apparatus of data extraction, including: sampling a signal and obtaining a plurality of sampled values, providing a reference sample quantity when the sampled values transit, providing a unit bit sample quantity according to the reference sample quantity, and corresponding each of the sampled values to each data bit of the signal according to the unit bit sample quantity.

Abstract: This invention discloses a method and an apparatus for reducing false alarm rate in preamble detection due to discontinuities between successive symbols in a received signal. The invention is usable in, e.g., a LTE compliant system. In one embodiment, the apparatus includes a filter for filtering the received signal to yield a filtered signal, and a correlator for correlating the filtered signal with a predetermined preamble. The apparatus further comprises a first multiplier for modifying the received signal before it is filtered, or a second multiplier for modifying the filtered signal before it is correlated, or both. The first multiplier multiplies the received signal with a first time-domain window function configured to substantially smooth discontinuities at symbol boundaries in the received signal. The second multiplier multiplies the filtered signal with a second time-domain window function configured to substantially suppress spikes present in the filtered signal around the symbol boundaries.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, systems, and program products for adapting data rate. The method includes receiving a data transmission at a data rate, identifying a first quantity of packets that were not adequately received, and using the first quantity to increase a packet loss level. A second quantity of improper bits in those packets that were adequately received at the data rate are identified, and the second quantity is used to increase a bit error level. As a result of having determined that the first value does not satisfy a first criterion for reducing the rate of the data transmission and that the second value does satisfy a second criterion for increasing the rate of the data transmission, an instruction is sent for causing the sending device to increase the rate of the data transmission.

Abstract: According to one embodiment, a quadrature error compensating circuit for acquiring an in-phase component signal and a quadrature component signal, includes a first filter, a first multiplier, a first subtractor, a second filter, a correlation calculating circuit. The first multiplier multiplies the in-phase component signal by a control value. The correlation calculating circuit calculates a cross-correlation value between an output of the first filter and an output of the second filter, and uses the cross-correlation value as the control value.

Abstract: The present invention provides a delay detector circuit that delivers performance at low cost and can reduce power consumption, and a receiver apparatus that uses this delay detector circuit. The delay detector circuit according to the present invention performs a part of decoding processing for decoding data transmitted by a transmitter apparatus based on a received wave of a two-phase modulation method. The receiver apparatus according to the present invention uses the delay detector circuit described above. Therefore the delay detector circuit and receiver apparatus of the present invention deliver performance at low cost and can reduce power consumption.

Abstract: A receiver unit of a communication device can employ multiple correlators for decoding the access address of a packet received from another communication device. A dynamically determined primary frequency offset is applied to a phase difference signal that is determined from an RF signal that comprises the packet. For each of a plurality of access address decoding chains of the receiver unit, a secondary frequency offset associated with the access address decoding chain is applied to the phase difference signal, the phase difference signal is correlated with a predetermined access address of the communication device, and a resultant correlation output is compared against a correlation threshold. One of the access address decoding chains that generated the correlation output that is greater than the correlation threshold is selected and the packet is demodulated based, at least in part, on the phase difference signal corresponding to the selected access address decoding chain.