Abstract: A demodulation mask bitmap includes binary mask values. Each mask value corresponds to an input resource element to a demodulator. For each mask value of a first state, a demodulation engine of the demodulator is not clocked and the demodulator outputs a zero-valued resource element. For each mask value of a second state, the demodulation engine is clocked, the input resource element is demodulated, and the demodulator outputs a demodulated resource element. A demodulation mask bitmap is designed to mask pilot resource elements and corrupted resource elements. Power is conserved by not clocking the demodulation engine for corrupted and pilot resource elements. Subsequent LLR generation and decode operations are simplified. Decoder performance is improved because the decoder does not decode LLR values derived from corrupted resource elements and/or resource elements not relevant to the reconstruction of a communicated message.

Abstract: A receiver for recovering data from Orthogonal Frequency Division Multiplexed (OFDM) symbols. The receiver includes a signalling and guard detector, which includes a correlator comprising a first branch having a first moving averaging filter, which is arranged to form pre-amble average correlated samples by averaging a value of a plurality of pre-amble correlated samples within a moving window, the plurality of samples averaged within the moving window corresponding to a temporal length of the post-amble (Tb), a second branch having a second moving averaging filter, which forms post-amble average correlated samples by averaging a value of a plurality of post-amble correlated samples within a moving window, the plurality of samples averaged within the moving window corresponding to a temporal length of the pre-amble (Tc), a combiner, which combines the averaged pre-amble correlated samples and the averaged post-amble correlated samples to form output correlation samples.

Abstract: A method includes configuring a transmitter and a receiver with first precoding matrices for mapping onto N transmit antenna ports of the transmitter R1?N data streams. Each first precoding matrix is derived from respective second and third precoding matrices, which are configured for mapping onto respective numbers of antenna ports that are less than N. A set of precoding matrices is defined for mapping r<R1 data streams onto the transmit antenna ports. Each matrix in the set includes a subset of columns of a given matrix selected from the first precoding matrices. A candidate matrix is included in the set when the candidate matrix cannot be expressed as a weighted permutation of the columns of another matrix in the set. The data streams are mapped onto the transmit antenna ports using a precoding scheme based on one of the first precoding matrices.

Abstract: Methods and apparatus for recovering data from communication signals apply estimated distribution algorithms. Estimated probability distributions may be constructed to avoid deterministic values. Non-converging data elements may be resolved by performing selective local searches. Embodiments recover data from space-time-frequency block coded signals. A data receiver comprises two or more antennas and signal detectors for detecting signals received at the antennas. A data detection module constructs a fitness function based on the received set of signals and generates additional possible solution sets by an iterative process in which the fitness of possible data sequences are evaluated using the fitness function.

Abstract: Disclosed is a system and method for improving the linearity of a clock and data recovery (CDR) circuit. In one embodiment, a data stream is received, and the phase of a clock signal is adjusted using two interpolators. The phase of the output signal of the second interpolator is adjusted simultaneously with, and complementary to, adjusting the phase of the first interpolator. The first interpolator's output signal is injected into a first delay cell in a delay loop having a plurality of delay cells, and the output of the second interpolator is inactivated. When the maximum phase of the first interpolator's output signal is reached, the second interpolator's output signal is injected into another one of the delay cells, and the first interpolator's output signal is inactivated. The data stream is then recovered using the output of the delay loop as a clock signal.

Abstract: An apparatus for adaptively decoding based on a channel variation at a receiver of a communication system supporting an Alamouti mode is provided. The apparatus includes a channel variation estimator for estimating the channel variation; a channel estimator for estimating a channel value of successive channel periods or a channel value of each channel period by comparing the estimated channel variation with a threshold; an Alamouti decoder for decoding a receive signal using an Alamouti method when the estimated channel variation is less than or equal to the threshold; and a Spatial Multiplexing (SM) decoder for decoding the receive signal using an SM method having a square channel matrix when the estimated channel variation is greater than the threshold.

Abstract: Implementations of improved transmission of orthogonal space time codes are disclosed.

Abstract: A digital broadcasting system and method of processing data are disclosed. Herein, a transmitting system within the digital broadcasting system includes a byte-symbol converter, an interleaving unit, a block formatter, and a trellis encoding module. Herein, the byte-symbol converter converts inputted mobile service data to symbol units. The interleaving unit is provided with (N?1) number of block interleavers in parallel, and interleaves the symbols outputted from the byte-symbol converter. The block formatter controls output orders of the mobile service data being inputted and data being outputted from each block interleaver within the interleaving unit. The trellis encoding module is provided with a plurality of trellis encoders in parallel, and enables each trellis encoder trellis-encode the mobile service data.

Abstract: A method and apparatus for detecting variations in the forward wireless channel in a wireless communication system. A plurality of reverse channel estimates in a reverse wireless channel are monitored, and a rate of change is measured between the plurality of reverse channel estimates in the reverse wireless channel. A rate of change in the forward wireless channel is estimated from the rate of change between the plurality of reverse channel estimates in the reverse wireless channel. If the estimated rate of change in the forward wireless channel exceeds a threshold, an update of a steering matrix is initiated.

Abstract: A circuit for transmission and reception of multi-channel communications is disclosed. The transmitter path includes a digital modulation circuit receiving multiple channel binary data, and for each channel generating a digital representation of the data. A digital-to-analogue (D/A) conversion circuit (140-146) is provided for each data channel. Each D/A conversion circuit receives and converts respective channel digital representations to produce a resultant band limited analogue signal (148-154). The band limitation arises due to a characteristic of said channel digital representations. A bandpass filter (156-162) receives and filters each analogue channel signal. The band width to the start of the stop band of each bandpass filter is wider than a respective band limited analogue channel signal and wider than the Nyquist bandwidth arising from the sampling rate of said D/A conversion circuit. In this way, signal power in unwanted Nyquist zones is effectively removed.

Abstract: A modulation device includes a signal input for receiving a data stream to be modulated and a first and a second signal output. At least one first complex component is derived from the data stream in a coding device. A first and a second high-frequency signal are output via the signal outputs. The first and second high-frequency signals are derived from the at least one first complex component and are distinguished by the fact that the second high-frequency signal has a phase shift of substantially 90° with respect to the first high-frequency signal.

Abstract: The present disclosure relates generally to a system and method for superposition coding and interference cancellation in a multiple input multiple output (MIMO) system. In one example, the method includes demultiplexing a signal of a user into at least first and second signal portions and demultiplexing a signal of another user into at least third and fourth signal portions. Superposition coding is performed on the first and third signal portions to form a first composite signal and performed on the second and fourth signal portions to form a second composite signal. The first composite signal is transmitted via at least one antenna of a MIMO system and the second composite signal is transmitted via at least another antenna of the MIMO system.

Abstract: A sounding reference signal transmission method which is efficient in an uplink wireless telecommunications system using a multiple antenna technique and sounding reference signal hopping. A terminal using the multiple antenna technique is equipped with a plurality of antennas, and a base station receives the sounding reference signal transmitted from these antennas and estimates the uplink channel state of each antenna. Moreover, the sounding reference signal performs frequency hopping so that the base station determines the channel condition for the entire bandwidth to which data is transmitted in the uplink system. The sounding reference signal is transmitted through an antenna pattern in which the sounding reference signal can be transmitted through the entire data transmission bandwidth of the uplink system for each antenna of the terminal without additional overhead in this environment.

Abstract: A data receiving apparatus includes a measuring section configured to measure a first pulse width of a first pulse, a second pulse width of a second pulse, and a third pulse width of a third pulse. The first pulse, the second pulse, and the third pulse are sequentially and continuously received by putting a portion of a second signal level different from the first signal level between the first and second pulse and the second and third pulse. A first comparing section performs a first determination based on a measured value of the first pulse width and a measured value of the second pulse width, and a second comparing section configured to perform a second determination based on the measured value of the second pulse width and the measured value of the third pulse width, based on the first determination and the second determination.

Abstract: Methods and apparatus are provided for adapting one or more equalization parameters in a communications system by reducing group delay spread. According to one aspect of the invention, one or more equalization parameters in a communications system are adapted by detecting one or more predefined run length patterns in a received signal, such as a plurality of consecutive same-valued bits; evaluating a transition latch value for each of the detected predefined run length patterns, wherein the transition latch value provides an indication of whether the received signal is under-equalized or over-equalized; and adjusting the one or more equalization parameters of the communications system based on the evaluation of the transition latch value. The adjusted equalization parameters may be employed to equalize intersymbol interference. A data eye monitor can be employed to evaluate the transition latch value.

Abstract: A communication method includes: (a) dividing one bit data group into a plurality of bit groups, the one bit data group being taken out from a plurality of bit data groups defined by a communication protocol for transmitting predetermined information, and exerting no substantial influence on the predetermined information even when arbitrarily inverting a value of the bit; (b) determining whether or not the values of the bits constituting the bit group are all the same by each of the plurality of bit groups divided into in step (a); (c) inverting at least one of the values of the bits of the bit group determined in step (b) that the values of the bits are all the same; and (d) arranging the plurality of bit groups, each of which has at least one of the values of the bits inverted in step (c), in the plurality of bit data groups except the one bit data group at regular intervals.

Abstract: A digital slicing device is provided for making a numerical value determination with respect to an inputted modulated symbol so as to output a corresponding symbol. The digital slicing device includes a demodulating unit, a slicing unit and a re-modulating unit. The demodulating unit is for collecting at least two successive modulated symbols and for demodulating the two modulated symbols according to a modulation algorithm so as to generate two demodulated symbols. The slicing unit is for rounding the two demodulated symbols so as to generate two rounded demodulated symbols. The re-modulating unit is for re-modulating the two rounded demodulated symbols according to the modulation algorithm so as to generate two re-modulated symbols corresponding to the two modulated symbols. The two modulated symbols are generated simultaneously through conversion using the modulation algorithm.

Abstract: The present invention employs a pilot scheme for frequency division multiple access (FDM) communication systems, such as single carrier FDM communication systems. A given transmit time interval will include numerous traffic symbols and two or more short pilot symbols, which are spaced apart from one another by at least one traffic symbol and will have a Fourier transform length that is less than the Fourier transform length of any given traffic symbol. Multiple transmitters will generate pilot information and modulate the pilot information onto sub-carriers of the short pilot symbols in an orthogonal manner. Each transmitter may use different sub-carriers within the time and frequency domain, which is encompassed by the short pilot symbols within the transmit time interval. Alternatively, each transmitter may uniquely encode the pilot information using a unique code division multiplexed code and modulate the encoded pilot information onto common sub-carriers of the short pilot symbols.

Abstract: In a method for estimating a deviation between a free-running transmitter clock and a reference clock, at a receiver stationary with respect to a transmitter, a transmitter signal generated by the transmitter on the basis of the transmitter clock is received. On the basis of the reference clock, a time of arrival of the transmitter signal and a beat phase of the transmitter signals carrier is determined. On the basis of a clock error model, the time of arrival and the beat phase, the deviation between the transmitter clock and the reference clock is estimated. The clock error model is derived by fitting a correlation function of a stochastic model to a measured auto correlation function of the transmitter clock. Deviations for a plurality of transmitters may be estimated and the transmitters may be virtually synchronized based on the estimations.

Abstract: A method for loading image data required by a motion estimation into a storage medium, the method includes: determining if an overlap portion between a current search range and a previous search range exists; and if the overlap portion exists; keeping image data corresponding to the overlap portion stored in the storage medium; identifying a non-overlap portion between the current search range and the previous search range; dividing the non-overlap portion into at least one sub-block; and loading image data corresponding to each sub-block into the storage medium for utilization by the motion estimation.