Abstract: A system and method are disclosed for performing on die jitter tolerance testing. A set of clocks are generated based on an input signal. The set of clocks include in an in-phase signal based on the data switching edge of the input signal. Additionally, the set of clocks include an inverted clock phase shifted by 180 degrees, and a pair of clocks phase shifted positively and negatively by a certain number of degrees, ?. Data input is sampled based on the inverted clock and the two phase shifted clocks. The eye opening of the input signal can be determined based on whether each of the inverted clock and the two phase shifted clocks sample the correct data from the input signal at various ? values.

Abstract: A direct conversion transmitter has a mixer stage to up-convert an input signal to the frequency of a local oscillator (LO). A DC offset circuit is coupled to an input signal port to apply a set of DC offset signal values. A processor determines a set of optimal DC offset signal values by no more than three differential spectral measurements made at the transmitter output port with a test signal applied at the input port. Optimal DC offset signal values are those that, when applied to the input signal at the input port of the transmitter, minimize an LO leakage component of the transmit signal at the output signal port of the transmitter. The optimal DC offset values are stored in memory and retrieved and applied to information bearing signals provided as the input signal once those optimal DC offset values have been determined.

Abstract: A method for controlling DSL transmission power includes: determining a group to which a line belongs, and selecting a representative line from each group to form a line model; obtaining a crosstalk model of the line model; obtaining Transmit Power Spectrum Density (TxPSD) of each representative line in the line model according to the crosstalk model, and converting the TxPSD into a spectrum control parameter; and enhancing the line rate according to the spectrum control parameter. An apparatus for controlling DSL transmission power is also disclosed. Through the method, the transmission power of the band that incurs serious line crosstalk is restricted, and the line that incurs serious crosstalk can achieve higher transmission rates. Therefore, the adverse impact from the crosstalk between xDSL lines is reduced, and the line works in the optimum state.

Abstract: For channel estimation in a spectrally shaped wireless communication system, an initial frequency response estimate is obtained for a first set of P uniformly spaced subbands (1) based on pilot symbols received on a second set of subbands used for pilot transmission and (2) using extrapolation and/or interpolation, where P is a power of two. A channel impulse response estimate is obtained by performing a P-point IFFT on the initial frequency response estimate. A final frequency response estimate for N total subbands is derived by (1) setting low quality taps for the channel impulse response estimate to zero, (2) zero-padding the channel impulse response estimate to length N, and (3) performing an N-point FFT on the zero-padded channel impulse response estimate. The channel frequency/impulse response estimate may be filtered to obtain a higher quality channel estimate.

Abstract: A method of channel estimation includes receiving a signal after transmission over a media having a plurality of sub-carriers in a frequency band. The signal is preprocessed including performing a fast Fourier transform (FFT) to generate a plurality of frequency-domain samples. Channel estimating is applied to the plurality of frequency-domain samples using (i) least squares (LS) estimation, wherein the LS estimation generates intermediate LS channel estimates for each of the sub-carriers, and (ii) frequency-domain filtering and scaling the intermediate LS channel estimates. The frequency-domain filtering uses a common frequency-domain filter consisting of a single filter coefficient vector having a plurality of frequency-domain filter coefficients to generate refined channel estimates for each of the plurality of sub-carriers.

Abstract: The present invention relates to a method for configuring, for each of one or more ranks in the DAS (distributed antenna system), a codebook for a DAS, including pre-coding matrices for the DAS, wherein the matrices include information on at least one or more antennas used for communication with a specific terminal, from among the whole antenna of the base station which belongs to the DAS, and information on the ratio of electric power allocated to each of the antennas of the base station. The present invention also relates to a method for transmitting a signal which is pre-coded using the thus-configured pre-coding matrices for the DAS.

Abstract: In an orthogonal frequency division multiplex (OFDM) modulated wave transmitter apparatus, a symbol mapping circuit and a serial/parallel (S/P) converter generate an OFDM symbol signal from transmission data. An inverse fast Fourier transform (IFFT) circuit, a parallel/serial (P/S) converting and guard interval (GI) adding circuit, a timing adjusting circuit, a digital/analog (D/A) converter, a frequency converter, a local oscillator and an analog filter generate an OFDM modulated wave signal from the OFDM symbol signal. A power amplifier (PA) control circuit limits a band of the OFDM symbol signal and generates a PS control signal and a PA control signal. A PA designates a voltage supplied from a DC/DC converter as a PS voltage and amplifies and outputs the OFDM modulated wave signal based on the PA control signal.

Abstract: A first preamble for a first data unit includes a first long training field and a first signal field modulated according to a first technique. The first data unit is generated according to a first data unit format and includes the first preamble. A second preamble, generated for a second data unit, includes a second signal field and a second long training field. Information in the second signal field is repeated and/or the second long training field is generated so that a duration of the second long training field is longer than a duration of the first long training field. A portion of the second signal field is modulated according to a second technique or a portion of the second long training field is modulated according to the second technique to signal to a receiver that the second data unit is formatted according to a second data unit format.

Abstract: A transmission apparatus and method for transmitting signals in a multi carrier transmission system comprises a modulator, a band information generator that generates band information defining the frequency bands corresponding to all of the data streams carried within that frequency channel, said band information including a tuning frequency indicator indicating a tuning frequency and a tuning frequency type indicator indicating the type of tuning frequency indicated by said tuning frequency indicator, wherein said type is selected from a group comprising at least a first type indicating a tuning frequency of a frequency band and a second type indicating a center frequency of a frequency channel, and a transmitter.

Abstract: A cooperative multiple-input multiple-output system based on partial Zadoff-Chu sequences and a synchronization method thereof are disclosed, and the system comprises a plurality of transmitters and a receiver. Each transmitter's training signal is disposed in a subband having a length of V, and the training signal is converted into a time domain signal. The receiver receives the time domain signals of the cooperating transmitters. Each transmitter extracts V successive samples from any region of a Zadoff-Chu sequence having a length equal to a multiple of V and the samples are disposed in an exclusive subband as the training signal. When the training signals of cooperating transmitters are converted into time and frequency domain signals, the training signals of all the transmitters are separated from each other to suppress mutual interference in both time and frequency domains and to improve the performance of synchronization.

Abstract: Methods and devices that establish communication between a first station and a second station are provided. To this end, an identifier, which identifies the first station and the second station as communication partners for communication, is transmitted between the first and second stations on a first partial connection. After receiving the identifier, communication is started between the first and second stations via a communication connection, wherein the transmission of the identifier via the first partial connection and the communication connection are based on different physical connections. The methods and systems can be used for loading or unloading processes of electrical vehicles, such as autonomous systems in the hospital field, or for vehicles for personal transportation. The methods and systems may provide reliable and cost-effective communication between the first and second stations.

Abstract: In some embodiments, a receiver circuit is configured to receive a modulated signal from a transmitter that is galvanically isolated from the receiver circuit. The receiver circuit is configured to demodulate the modulated signal by using two comparator circuits that respectively detect the presence or absence of first and second signal states of a carrier signal. Based on the detection of the first and second states, the receiver circuit determines whether the carrier signal is present or absent in the modulated signal to determine a demodulated value of the modulated signal.

Abstract: Provided is a wireless communication system including a first communication device configured to perform spectral shaping on a frequency signal and transmit the signal, and a second communication device configured to receive the signal transmitted by the first communication device, and the second communication device includes: a frequency averaging unit configured to dividing information on transmission power gains in all the discrete frequencies into blocks by a plurality of discrete frequencies, information being necessary for the first communication device to perform the spectral shaping; a quantizing unit configured to quantize representative values of the blocks; and a transmitting unit configured to transmit the quantized signals.

Abstract: A transmission method and device are provided for taking account of an echo. The method and the device adapt the send power mask to take account of an echo's power estimated on the basis of an echo function, the echo being due to the transmission by a transmission channel of a sequence sent by the sender device.

Abstract: A method for carrier frequency tracking of a received signal having a burst structure includes dividing each burst into a number of segments. The carrier frequency offset of a first segment within a burst is measured to obtain a first segment carrier frequency offset measurement value. The carrier frequency offset of a second segment within the burst is corrected by a second segment carrier frequency offset correction value based on the first segment carrier frequency offset measurement value.

Abstract: Every k (k?2) sampling values of sampling values in a time series obtained by sampling reception signal from GPS satellite are selected, and addition-subtraction of the selected k sampling values is performed by changing the combinations of addition and subtraction. Using addition-subtraction results of a combination corresponding to time-series change in code values of a replica code from among the combinations of addition and subtraction, a correlation result of the reception signal and the replica code is calculated. The satellite signal of the GPS satellite is acquired using the correlation result.

Abstract: Implementation and operation of a multiple protocol receiver are described herein. In one example, a multiple protocol receiver in a node may alternate between first and second states. In a first state, the multiple protocol receiver listens simultaneously for a plurality of differently modulated signals. Such listening may be performed in a parallel manner, wherein a plurality of preamble detection processes each listens for a specific preamble. The listening may result in detection of a preamble of a packet, which triggers transition to the second state. The detected preamble may indicate a protocol used in transmission of the packet. The received packet may then be demodulated according to, for example, a data rate, synchronization, redundancy and/or other factors indicated by the protocol. The received packet may be utilized by the node or retransmitted. The multiple protocol receiver may return to the first state to repeat and continue the procedure.

Abstract: A communication system includes digital signals that carry data and correspond to channels of a composite signal to be transmitted across a communication channel. Active channels are detected and used to configure digital processing. In one embodiment, active channels are detected, where a particular active channel corresponds to the presence of a particular one of the digital signals. Active channel detection may be used to configure pre-distortion of a composite signal to be transmitted to compensate for distortion in a digital-to-analog converter. Likewise, active channel detection may be used to optimize the configuration of an up-converter. In one embodiment, a programmable device is configured based on detected active channels into a plurality of different configurations.

Abstract: Control systems for mounting in a vehicle are configured for transmitting a control signal to a receiver associated with a remote device. A control system receives a first control signal associated with a first transmission scheme. The system determines a bit pattern of the first control signal, and, based on the determined bit pattern, the system determines a second transmission scheme.

Abstract: Methods and systems adaptively equalizing an analog information signal, the method including sampling the analog information signal to provide analog samples including post-transition samples and steady-state samples, and equalizing the analog samples to produce equalized analog samples. The equalizing includes determining a difference between an average post-transition amplitude associated with at least one of the post-transition samples and an average steady-state amplitude associated with at least one of the steady-state samples, and adjusting an equalization coefficient to adjust the difference between the average post-transition amplitude and the average steady-state amplitude.