Abstract: This disclosure relates systems and methods for a high bandwidth modulation and transmission of communication signals.

Abstract: For example, a method of detecting frame marker quality includes: detecting, in a bit-stream sent from a first component to a second component of a common hardware unit, a frame marker having a bit pattern different from an uncorrupted frame marker specified by a communication protocol; and assigning a quality level indicator to the frame marker based on a difference between said bit pattern and a bit pattern of said uncorrupted frame marker.

Abstract: A transmitter including a plurality of input lanes, a substitutor module, and an interleaver module. The plurality of input lanes is configured to receive input symbols including data symbols and idle symbols, wherein the input symbols are arranged into columns of concurrently received input symbols, and wherein each of the columns includes one input symbol from each of the plurality of input lanes. The substitutor module is configured to, at intervals, replace one of the columns with a column of alignment symbols. The substitutor module is further configured to replace an immediately subsequent one of the columns with a column of disposable symbols; and replace one or more immediately subsequent ones of the columns with columns of boundary symbols uninterrupted by disposable symbols. The interleaver module is configured to interleave symbols from the substitutor module between a first transmit lane and a second transmit lane.

Abstract: An apparatus and method for transmitting/receiving an S-SCH in an Institute of Electrical and Electronics Engineers (IEEE) 802.16m wireless communication system are provided. A method for transmitting, by a transmitter, a Secondary Synchronization CHannel (S-SCH) in a communication system includes generating a sequence depending on a cell IDentification (ID), determining a subcarrier set comprising subcarriers to map the generated sequence, based on a Fast Fourier Transform (FFT) size and a segment ID, and mapping the generated sequence to the subcarriers of the determined subcarrier set.

Abstract: A method for blindly detecting a precoding matrix index used to transmit a data or control signal is provided. The method includes receiving at a mobile station (102) a common reference signal and user specific data and control signal weighted by precoding matrix. An objective function is applied to the received reference signal and user specific data and control signal that minimizes the objective function for each of at least one rank used to transmit the received user specific data and control signal and each of known possible modulation constellations used to transmit the received data/control signal to determine the precoding matrix index (PMI).

Abstract: An effective data sequence based timing error detector (EDS-TED) for baseband transmission system using Tomlinson-Harashima Precoder is disclosed. The EDS-TED extracts timing error information embedded in the received signal to build up autocorrelation between the ESD signals and minimize the mean square error between the received and desired EDS so as to improve the performance of the TED in terms of Peak-to-Peak Jitter and TED gain. Thus the quality of the received signal increases and the error rate decreases.

Abstract: An OFDM transmitter and receiver realizing high-speed cell search and having a reducible circuit scale. An OFDM transmitter includes an SCH inserting section for constructing a frame where a synchronization sequence in a predetermined position from the head of a first sub-frame is arranged and a synchronization sequence composed of the symbols of the former synchronization sequence and the symbols whose I, Q components are interchanged is arranged in a predetermined position from the head of a second sub-frame adjacent in the time-axis direction to the former sub-frame, an IFFT section, a P-SCH conversion section, and an RF transmitting section for transmitting this frame. Thus, the receiving end of the frame can locate the position of either synchronization sequence and determine the frame timing from that position, thereby increasing the speed of the cell search.

Abstract: An approach is provided for supporting frame synchronization in a digital broadcast and interactive system. A transmitter includes an encoder that outputs a Low Density Parity Check (LDPC) codeword. The transmitter also includes a framing module generates a LDPC coded frame in response to the LDPC codeword, and appends a physical layer signaling field to the LDPC codeword for specifying modulation and coding information associated with the LDPC coded frame. The physical layer signaling field is encoded with a Forward Error Correction (FEC) code and has an embedded framing structure to assist with frame synchronization. The above arrangement is particularly suited to a digital satellite broadcast system.

Abstract: Described is an apparatus for suppressing spurious spectral lines in a frame based bit-serial data stream, in which frames include payload data and frame markers. The apparatus includes means (16) for randomizing first frame marker elements (START) in a first position within each frame and means (18) for correlating second frame marker elements (STOP) in a second position within each frame with the randomized first frame marker element.

Abstract: A method of formatting a digital broadcast transport stream packet, a digital broadcast transmitter, and a signal processing method thereof, includes constructing a transport stream packet that includes a stuffing region for an insertion of a known supplementary reference signal (SRS) data therein, randomizing the packet that includes the stuffing region is randomized, and the SRS data is inserted into the stuffing region of the randomized packet. Adding a parity for an error correction to the packet into which the SRS data has been inserted, the packet to which the parity has been added is interleaved, and a trellis encoding of the interleaved packet is performed. Inserting a segment sync signal and a field sync signal into the trellis-encoded packet, and a vestigial side band (VSB) modulation and an RF conversion of the packet are performed to transmit the VSB-modulated and RF-converted packet.

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 device for transport stream processing is provided. The device includes a plurality of data inputs and a transport stream re-multiplexer for receiving a plurality of data streams from the plurality of data stream inputs and multiplexing the data streams into a transport stream. A transport stream processor receives the transport stream, de-multiplexes the transport stream to process one or more of the data streams, and provides the processed data stream to the transport stream re-multiplexer as one of the plurality of data streams.

Abstract: Apparatus, systems, and methods are provided for transmitting messages over a serial interface. A method comprises receiving a first signal at a first time and receiving a second signal at a second time, the second time being after the first time. If a difference between the second time and the first time is less than a threshold time period, the method comprises generating a first message that is representative of the first signal and the second signal and transmitting the first message over the serial interface. In accordance with one embodiment, the threshold time period is equal to one half of an interface acquisition delay time period associated with the serial interface.

Abstract: In a method of demapping a tributary from a first frame into a second frame, the first frame has a plurality of tributary words and a synchronization word, and first and second counters are provided. The first counter is increased by a first value at each dock cycle of the second frame, and reading operations are performed according to the second counter. Synchronization information, generated according to the synchronization word, is used to change between first and second states. When in the first state, the second counter is synchronized to the first counter at each clock cycle of the second frame; and, when in the second state, the second counter is synchronized to the first counter at a predetermined instant of the second frame, the second counter increasing by a second value at each clock cycle of the second frame wherein the reading operation is performed.

Abstract: A system including a magnitude measuring module, an energy normalization module, and a metric generation module. The magnitude measuring module is configured to measure magnitudes of real portions of differentially demodulated signals, wherein the differentially demodulated signals are generated by differential demodulation of signals received from a base station. The energy normalization module is configured to generate a sum of energies of a plurality of subcarriers included in the signals received from the base station. The metric generation module is configured to generate a plurality of metrics for a plurality of symbols included in the signals received from the base station. The metric generation module is further configured to detect, based on the plurality of metrics, a preamble symbol included in the signals received from the base station.

Abstract: A method from transmitting data via multiple antennas. The method contemplates modulating data to be transmitted into a plurality of modulated symbols, encoding each pair of modulated symbols from among said plurality of symbols in accordance with a transmission diversity scheme to result in a plurality of 2 by 2 matrices, with each 2 by 2 matrix corresponding to each pair of modulated symbols, orthogonally spreading the plurality of 2 by 2 matrices to generate an output matrix, and transmitting the symbols in the output matrix via a plurality of antennas by using either a space time transmission diversity scheme, a space frequency transmission diversity scheme, or a combination of a space time transmission diversity scheme and a space frequency transmission diversity scheme.

Abstract: A method of determining a residual frequency offset between a transmitter and a receiver in a transmission of data via a communication channel, is described, wherein the message is transmitted from the transmitter to the receiver via the communication channel and the message comprises at least one short preamble (201), at least one long preamble (202) and user data (203). The at least one long preamble (202) comprises residual frequency offset determination information based on which the residual frequency offset is determined.

Abstract: A permuted sequences combination uses a frame structure in which two sync words, each comprising M complex symbols, are appended at the frame start. One benefit is the reduction of the large variance of the timing estimation error in the conventional correlation method. In at least one embodiment, the first sync word, {right arrow over (s)}1, is a predetermined constant amplitude zero autocorrelation (CAZAC) sequence. The second sync word, {right arrow over (s)}2, is a permutation of the first such that the combination of the two received sync signal vectors perform sliding window processing where the peak occurs at the correct frame start. The permuted sequences combination can be used in both AWGN channel and multi-path environments.

Abstract: To make Flying-Adder architecture even more powerful, a new concept, time-average-frequency, is incorporated into the clock generation circuitry. This is a fundamental breakthrough since it attacks the clock generation problem from its root: how is the clock signal used in real systems? By investigating from this direction, a much more powerful architecture, fixed-VCO-Flying-Adder architecture, is created. Furthermore, based on fixed-VCO-Flying-Adder frequency synthesizer and time-average-frequency, a new type of component called Digital-to-Frequency Converter (DFC) is born.

Abstract: A method for determining the synchronization code under a standard mobile imaging architecture is provided. This method is essentially to solve any possible error occurring as transferring the images among the mobile devices. If any error is occurred to the transferred bit stream, it will cause fault in the image data. Consequently, the present invention provides an approach to compare every input data with iterative comparison operation, so as to obtain the position of synchronization codes under SMIA. Therefore, the correct synchronization code will solve the possible error translation.

Abstract: A sync detection device and method for a GNSS receiver. In modernized GNSS, each satellite transmits a data signal and a pilot signal. Correlations are performed between a data symbol stream converted from the data signal with possible hypotheses to find a leading edge of a frame of the data signal (i.e. frame sync detection) and between a pilot symbol stream converted from the pilot signal with possible hypotheses to find a leading edge of a code sequence of the pilot signal (i.e. pilot sync detection). The possible hypotheses for the frame sync detection are selected according to a result of pilot sync detection when pilot sync is done. Frame sync can be efficiently achieved since a range of the selected possible hypotheses is quite limited.

Abstract: A technique includes receiving a datum indicative of a candidate delimiter in a receiver; and processing the datum in a machine to determine whether the datum indicates a synchronization delimiter. The processing includes comparing the candidate delimiter with a reference delimiter to identify at least one error in the candidate delimiter; and basing the determination of whether the datum indicates the synchronization delimiter at least on a bit position of of each error.

Abstract: Performing cell search in a wireless communications system includes receiving a preamble signal, match filtering the preamble signal with a pseudo noise sequence to form a filtered preamble signal of a plurality of filtered preamble signals, choosing a largest filtered preamble signal from the plurality of filtered preamble signals, and determining an estimated pseudo noise sequence index and an estimated integer part frequency offset according to the largest filtered preamble signal.

Abstract: The present invention provides a method of early starting the operation of a descrambler. The method comprises the steps of receiving a, synchronous byte of a transport packet in a group of m packets, where m is an integer, generating an alignment index to indicate a location of the synchronous byte, delivering the alignment index to the descrambler, and loading an initialization sequence to the descrambler in accordance with the alignment index and starting an operation of the descrambler.

Abstract: Apparatus and methods for accessing a wireless telecommunications network by transmitting a random access signal. The random access signal includes a random access preamble signal selected from a set of random access preamble signals constructed by cyclically shift selected root CAZAC sequences. The random access signal may be one or more transmission sub-frames in duration, the included random access preamble sequence's length being extended with the signal to provide improved signal detection performance in larger cells and in higher interference environments. The random access signal may include a wide-band pilot signal facilitating base station estimation of up-link frequency response in some situations. Each of the plurality of available random access preamble sequences may be assigned a unique information value. The base station may use the information encoded in the random access preamble to prioritize responses and resource allocations.

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: An offset determination arrangement includes a comparator device to compare an input signal with a reference value. A synchronization unit is provided to forward a comparison result of the comparator device as a function of a synchronization signal which can be generated by a synchronization clock generator. The synchronization signal includes clock pulses in which at least one clock period between adjacent clock pulses is shorter than a precedent clock period. The offset determination arrangement further includes an approximation unit to generate a compensation signal corresponding to an offset of the input signal as a function of the forwarded comparison result.

Abstract: Provided is a method for detecting frame sync and frame structure in a satellite broadcasting system. The method for detecting frame sync and frame structure includes the steps of: calculating differential correlation values of reception symbols; generating index sequences of reception symbols whose differential correlation values calculated above exceed a threshold value; calculating positions estimated as frame start points which correspond to a total frame number based on the number of symbols per frame for each frame structure; and detecting frame sync and frame structure based on the umber of positions where the above-calculated frame start point estimated positions and the above-generated index sequences are matched.

Abstract: A method and system for performing clock calibration and de-skew on a multi-lane high speed serial interface is presented. Each of a plurality of serial lane transceivers associated with an individual bit lane receives a first data frame, comprising a training sequence header pattern. Based on each of the first data frames, the plurality of serial lane transceivers de-skew a plurality of data frames and generate a plurality of event signals. Using the plurality of event signals, a core clock, having a first phase, is adjusted to be phase aligned with the slowest bit lane.

Abstract: A receiving apparatus includes a first receiver, a second receiver, a received signal synthesizer connected to the first and second receivers, a synchronizing signal synthesizer connected to the first and second receivers, and a synchronization detector connected to the synchronizing signal synthesizer. In this structure, synchronization determination is performed using a synchronizing signal of either the first or second receiver, and diversity reception is performed using the received signals of the first and second receivers.

Abstract: A Universal Mobile Telecommunications System (UMTS) receiver comprises an adjustable delay line, a secondary synchronization processor and a controller. The secondary synchronization processor performs frame synchronization on a received wireless signal that is provided via the adjustable delay line. The controller varies the sub-chip timing delays provided by the adjustable delay line until a measure of accuracy of the frame synchronization process exceeds a predetermined threshold, upon which frame synchronization occurs.

Abstract: A method and apparatus for generating a TSC in a communication system are provided, in which a pair of sequences A and B having auto-correlation and cross-correlation properties are generated and the TSC is generated by inserting guard sequences Z each having z zero symbols in the most significant bits of the sequences A and B.

Abstract: The present invention provides a unique manner of identifying the Frame boundaries in multiple identical/non-identical Synchronization Channels (SCHs) in different sub-frames via a new sub frame position difference method. The method implements the differences between the different sub-frames carried by the SCH. The sub frame identity, and hence the frame boundary, can be identified by calculating the difference between the positions, based on time or number of slots/sub-frames or any data packets, of the two subsequent slots/sub-frames or any identical data packets.

Abstract: A method is provided for estimating a frequency offset in a carrier signal caused by the Doppler effect. The method determines a frequency offset estimate by utilizing a multi stage estimation scheme. More specifically, the method determines the frequency offset estimate of a data frame by iteratively estimating the frequency offset by comparing different portions of the preamble. As the length of the sampled patterns varies, the frequency offset estimates vary in accuracy and range. The method may adjust frequency offset estimates that are out of range. Finally, the receiver obtains a frequency offset estimate for the data frame from a weighted combination of frequency offset estimates. This method is applicable in WiFi (IEEE 802.11a/g), WiMax (IEEE 802.16), and WAVE (IEEE 802.11p) systems.

Abstract: A deserializer including a plurality of registers, a sync detector, and a lost bit storage unit. If there is a phase difference between an external input data packet and a recovery clock signal transmitted together with the data packet, the sync detector generates an activated sync detect signal. The lost bit storage unit detects a data bit of the data packet corresponding to an activation point of the sync detect signal. The deserializer recovers the data packet by combining the detected data bit with the data packet.

Abstract: A method and an apparatus for synchronizing a data stream are disclosed. The method comprises: decoding the data stream to generate a decoded data stream and program clock references; generating a local clock reference; generating a simulated clock reference according to the program clock references and the local clock reference; comparing the local clock reference with the simulated clock reference; adjusting a processing timing of the decoded data stream according to the comparison result; and processing the decoded data stream according to the processing timing.

Abstract: A digitizer includes an analog to digital converter (ADC), a sampling frequency generator, and a controller. The ADC samples an IF signal to generate a digital signal. The sampling frequency generator is connected to the ADC and provides a sampling clock of variable frequency to the ADC. The controller is connected to the sampling frequency generator and determines frequency of the sampling clock.

Abstract: Serial data communication methods and apparatus using a single line are provided. The data communication methods may include: setting a rising edge of a serial pulse signal so that a cycle of the serial pulse signal begins therefrom; setting a falling edge of the serial pulse signal within the cycle of the serial pulse signal according to a data value recorded within the cycle of the serial pulse signal; and transmitting a packet formed by combining at least one cycle of the serial pulse signal in series via a single line.

Abstract: Disclosed is a system and a training sequence setting method for performing frame synchronization in a wireless communication system. A received signal is affected by a frequency offset due to an oscillator mismatch between the transmitter and the receiver, which is one of the main causes of performance degradation of frame synchronization. In a prior Constant Amplitude Zero Auto-Correlation (CAZAC) sequence, the larger the frequency offset becomes, the more conspicuously the performance degradation of the frame synchronization occurs. The proposed training is designed to maintain a prior CAZAC property during a differential detection so as to perform a differential detection-based frame synchronization sequence insensitive to the frequency offset. As a result of performance verification, the proposed training sequence indicates that its performance of the frame synchronization is irrespective of the frequency offset, and has a better performance than the prior CAZAC sequence and random sequence.

Abstract: A system for implementing an orthogonal frequency division multiplexing scheme and providing an improved range extension. The system includes a transmitter for transmitting data to a receiver. The transmitter includes a symbol mapper for generating a symbol for each of a plurality of subcarriers and a spreading module for spreading out the symbol on each of the plurality of subcarriers by using a direct sequence spread spectrum. The symbol on each of the plurality of subcarriers is spread by multiplying the symbol by predefined length sequences. The receiver includes a de-spreader module for de-spreading the symbols on each of the plurality of subcarriers. The de-spreader module includes a simply correlator receiver for obtaining maximum detection. The correlator produces an output sequence of a same length as an input sequence and the de-spreader module uses a point of maximum correlation on the output sequence to obtain a recovered symbol.

Abstract: A receiver in an impulse wireless communication. The receiver (300) includes a pulse-pair correlator (304) that receives a signal (316) and divides it into two signals for paths. One of the signals is input to signal multiplier (312) while another signal is delayed by a delay unit (310). The signal multiplier (312) multiplies the received signal (316) by a delayed signal (318). An integrator (314) integrates an output signal (322) over a designated period of time. An adding module (306) sums an output signal (324) from the integrator (314). An acquiring module (308) compares an summing-up output (326) from the adding module (306) with a predetermined threshold value to detect the existence of a transmitting-standard preamble.

Abstract: A system includes an input, a differential demodulation module, a magnitude measuring module, a summing module, and a metric generator module. The input receives input signals that include s sets of modulated sub-carriers carrying symbols, where s is an integer greater than or equal to 1. The differential demodulation module generates differentially demodulated signals based on the input signals. The magnitude measuring module measures magnitudes of real portions of the differentially demodulated signals. The summing module generates s sums, wherein each of the s sums is a sum of the magnitudes generated based on a respective one of the s sets. The metric generator module generates metrics for the symbols based on the s sums.

Abstract: A User Equipment (UE) receives and samples communication signals, where the communication signals have a time frame format, a transmission chip rate and a synchronization code associated with a time slot that includes a midamble that indicates a modulation of the synchronization code where a specified modulation of received synchronization codes identifies the timing for a timeslot in which data is to be received. The UE preferably includes a synchronization code determination circuit, a midamble determination circuit, and a phase modulation sequence detection circuit operatively associated with the midamble determination circuit. The UE can be configured for use with the low chip rate option of the Third Generation Partnership Project (3GPP) Universal Mobile Telecommunication System (UMTS) standards that employ a predefined set of downlink SYNC codes that point to midambles which indicate SYNC code modulation sequence to enables reading of data in a subsequent Broadcast Channel (BCH) message.

Abstract: An all-digital frequency synthesizer architecture is built around a digitally controlled oscillator (DCO) that is tuned in response to a digital tuning word (OTW). In exemplary embodiments: (1) a gain characteristic (KDCO) of the digitally controlled oscillator can be determined by observing a digital control word before and after a known change (?fmax) in the oscillating frequency; and (2) a portion (TUNE_TF) of the tuning word can be dithered (1202), and the resultant dithered portion (dkTF) can then be applied to a control input of switchable devices within the digitally controlled oscillator.

Abstract: A method for detecting a specific timing from a synchronization channel is described. A signal with a known sequence is received. Two or more correlation values between the received signal and the known sequence are calculated at two or more positions. The two or more correlation values are compared. A determination is made whether the position of the known sequence has been shifted based on the comparison. A specific timing of a synchronization channel is detected based on the determination.

Abstract: Methods and apparatus for reduction of a peak to average ratio for an OFDM transmit signal. In an aspect, a method is provided for reducing a peak to average ratio of a transmit waveform. The method includes obtaining a primary scrambler sequence, generating a secondary scrambler sequence having a length characteristic based on data to be scrambled, and combining the primary and secondary scrambler sequences to produce a PAR reduction sequence. In another aspect, an apparatus is provided for reducing a peak to average ratio of a transmit waveform. The apparatus includes a secondary generator configured to generate a secondary scrambler sequence having a length characteristic based on data to be scrambled, and combining logic configured to combine a primary scrambler sequence and the secondary scrambler sequences to produce a PAR reduction sequence.

Abstract: In a wireless 802.15.4 communication system, a method and system are provided for switching between a predetermined protocol transmission mode and a high-speed transmission mode by including signaling mode information in a data packet (330, 340) to instruct the receiver device (300) to demodulate at least a data payload using the predetermined transmission mode if the signaling mode information comprises a first predetermined value, and to demodulate at least the data payload using the high-speed transmission mode if the signaling mode information comprises a second predetermined value. The signaling mode information may be included in the SFD field of an 802.15.4 SHR structure to instruct the receiver how to demodulate or process the data packet, or may be included as desired anywhere in the data packet to instruct the receiver how to demodulate or process one or more subsequent data packets.

Abstract: A method and system is provided for detecting preambles in a multi-cell communication system. The method detects preambles reliably even in the presence of interference caused by multiple cells reusing the same frequency in the multi-cell communication system. After receiving a signal in the receiving period, the time domain signal is sampled and transformed into the frequency domain vector. The correlation vector is calculated with the frequency domain vector and pseudonoise code of the wireless station. The presence of a preamble is verified if the value in the correlation vector exceeds a predetermined threshold.

Abstract: The present invention relates to an apparatus and method of acquiring initial synchronization of a terminal in a mobile communication system. According to an exemplary embodiment of the present invention, one or more auto-correlation values of a preamble constituting a signal that is received from a base station are calculated. Averages of the calculated auto-correlation values according to samples are calculated, and then a peak value is detected among the calculated values. Then, a cell search is performed on the basis of the detected peak value, and a peak value from the result of the cell search is regularized. Then, the regularized peak value is compared with a predetermined reference value such that it is checked whether synchronization of a signal that has been searched is accurate or not.

Abstract: A data transmission process with auto-synchronised correcting code, auto-synchronised coder and decoder, corresponding transmitter and receiver. According to the invention, synchronisation management signals (HS, SS, ID) are formed and, under the control of these signals, a header is inserted before a data group and after it a correcting code. At receive end, these synchronisation management signals are reconstituted, the presence of a header is detected and any erroneous symbols are corrected. The invention also provides for an auto-synchronised coder and a decoder and for a transmitter and a receiver using them.