Abstract: Disclosed herein are a signal quality measuring apparatus for the WiBro system and a method thereof. The signal quality measuring apparatus for a WiBro system includes a WiBro signal reception unit, a preamble code correlation unit, a channel compensation/demodulation unit, and a control unit. The WiBro signal reception unit receives a WiBro signal from each base station. The preamble code correlation unit searches the WiBro signal for a number of preamble codes equal to the number of base stations for which measurement of signal quality measurement is required. The channel compensation/demodulation unit acquires the information of a Frame Control Header (FCH) section and a DownLink-MAP (DL-MAP) section with reference to the preamble codes found by the preamble code correlation unit, and demodulates the information of a unique number of the base station.

Abstract: A method of sending ultra-wide band signals via a plurality of sending antennas includes a phase for sending training sequences followed by a phase for sending data after which each antenna of the plurality of sending antennas sends a waveform using a Hermite pulse that is unique and orthogonal to the waveforms sent by the other antennas, and a device configured to perform the method.

Abstract: An apparatus and method for transmission and reception in a multi-user Multiple-Input Multiple-Output (MIMO) communication system are provided. In a transmitter, a filter portion receives quantized Channel State Information (CSI) and Channel Quality Information (CQI) from a receiver, calculates a transmit filter value using on the quantized CSI and the CQI, determines an appropriate AMC level for the receiver, and sends a pilot signal including the transmit filter value and information about the determined AMC level on subcarriers in one of a preamble and data symbols. An antenna is used to send the output of the filter portion and receives data from the receiver.

Abstract: A method for stable channel estimation to increase frequency band efficiency that is lost by using a pilot, and to reduce the complexity and the sensitivity to channel zero. The method includes generating an i-th symbol block Si including N carriers, performing an inverse fast Fourier transform (IFFT) operation on the i-th symbol block, and forming an orthogonal frequency division multiplexing (OFDM) symbol block. The method also includes attaching a guard interval sample in front of the i-th OFDM symbol block Ui and forming at least one OFDM symbol block Ui,cp. The method further includes modeling the formed OFDM symbol block Ui,cp with a channel finite impulse response (FIR) filter and estimating channel impulse response using signals yi received through a channel.

Abstract: Adjusting a local frequency source is disclosed. A local frequency comparison data is compared with a received frequency comparison data, wherein the local frequency comparison data reflects a difference, if any, between a locally measured AC frequency and a frequency generated using the local frequency source. The local frequency source is adjusted based at least in part on a result of the comparison.

Abstract: A channel equalizer includes a first transformer, an estimator, an average calculator, a second transformer, a coefficient calculator, a compensator, and a third transformer. The first transformer converts normal data into frequency domain data, where a known data sequence is periodically repeated in the normal data. The estimator estimates channel impulse responses (CIR) during known data intervals adjacent to each normal data block. The average calculator calculates an average value of the CIRs. The second transformer converts the average value into frequency domain data. The coefficient calculator calculates equalization coefficients using the average value, and the compensator compensates channel distortion of each normal data block using the coefficients. The third transformer converts the compensated data block into time domain data.

Abstract: Low power decision feedback equalization (DFE) through applying DFE data to input data in a data latch is disclosed. In one embodiment, a decision feedback equalization (DFE) system to remove a post cursor intersymbol interference (ISI) through feeding back previous data scaled with adaptive weights to the DFE system, with each slice of the DFE system may include a first set of decision feedback digital to analog converters (DACs) to generate a first DFE data obtained through the feeding back the previous data scaled with the adaptive weights and a first data latch to generate an output data of the each slice through applying the first DFE data to an input data of the each slice in the first data latch to remove a first delay caused by performing the applying the first DFE data to the input data of the each slice outside of the first data latch.

Abstract: A signal processing apparatus has a plurality of baseline wander correcting units, provided in a processing path in which a predetermined processing is performed on an input signal. At least one of the plurality of baseline wander correcting units includes a correction permission control unit that controls permission or rejection of correction, and baseline wander in the input signal is corrected sequentially by each of the plurality of baseline wander correcting units, based on a control of the correction permission control unit. The baseline wander correcting unit corrects the baseline wander by determining whether or not the baseline correction is to be effected or not, so that the wander of baseline can be efficiently corrected.

Abstract: The present invention provides an elevation based adaptive scheme for setting power threshold in the acquisition of navigational satellite signals. In an embodiment, the elevation based adaptive scheme uses a different series of power thresholds to acquire signals from satellites at different elevation angles instead of using one threshold for all satellites, as is done in the prior art. This scheme exploits the fact that the received signal power level depends on the elevation angle of the satellite at the receiver. This scheme also takes into account the antenna gain variation without having to measure the antenna gain variation.

Abstract: A phase calculation apparatus using a binary search is provided. The phase calculation apparatus includes a quarter surface preprocessor determining the bigger one between an absolute value of I component data and an absolute value of Q component data as horizontal component data and the smaller one as perpendicular component data, and detecting information on a phase region indicating an mth (m=1 to 8) phase region (the mth phase region is between (m?1) ?/4 and m ?/4 in which the I/Q component data are located; a phase representative value detector detecting phase representative values x corresponding to the horizontal component data and the perpendicular component data; and a quarter surface postprocessor calculating phase values of the I/Q component data based on the detected information about the phase region and the detected phase representative values x. The phase can be calculated using a limited memory, low complexity of calculation and regardless of the number of bits of I/Q component data.

Abstract: A system for performing adaptative multi-carrier code division multiple access (AMC-CDMA) includes first circuitry and modulator circuitry. The first circuitry determines a channel performance metric for each of a plurality of channels. The first circuitry determines at least one parameter of bit loading for each of the channels based on the channel performance metric. The modulator circuitry modulates AMC-CDMA signals using the parameters for bit loading in each of the channels for transmission over a wired connection.

Abstract: A technique for enhanced reconditioning equalizer filter chain for multi-carrier signals is described. The input to a transmitter chain is modified by an enhanced reconditioning equalizer filter chain, prior to being applied to the transmitter. The enhanced reconditioning equalizer filter chain modifies and smoothen the amplitude of the signal. The modified and smoothen signal has its picks reduced which results to lower Crest Factor. The input to the enhanced reconditioning equalizer filter chain could be a baseband, an intermediate frequency (IF) or radio frequency (RF) signal. When the signal is an IF or RF signal it needs to be down converted to baseband before applied to enhanced reconditioning equalizer filter chain. The enhanced reconditioning equalizer filter chain could be implemented in digital or analog domain.

Abstract: In one embodiment, a circuit is provided that includes: an impulse generator operable to provide a pulse train; a pulse position modulator having a splitting junction configured to receive the pulse train, the pulse position modulator including a plurality of n transmission lines, wherein n is an integer, the n transmission lines being selectably coupled in parallel between the splitting junction and a combining junction, the impulse generator driving each transmission line having a unique delay such that if the transmission line is selected, each pulse received at the splitting junction is uniquely delayed into a delayed pulse, whereby if all the transmission lines are selected, each pulse received at the splitting junction is uniquely delayed into a corresponding plurality of n delayed pulses; and a controller operable to select the transmission lines responsive to received words of n bits in length, each word arranged from a first bit to an nth bit, and wherein the transmission lines are arranged from a fi

Abstract: In one embodiment, a wafer scale radar antenna module (WSAM) is provided that includes: a substrate; a plurality of antennas adjacent the substrate; an RF feed network adjacent the substrate, the RF feed network coupling to a distributed plurality of amplifiers integrated with the substrate, wherein the RF feed network and the distributed plurality of amplifiers are configured to form a resonant network such that if a timing signal is injected into an input port of the RF feed network, the resonant network oscillates to provide a globally synchronized RF signal to a plurality of integrated antenna circuits, wherein each integrated antenna circuits includes a corresponding subset of antennas from the plurality of antennas, and wherein each integrated antenna circuit includes a pulse shaping circuit having a plurality of selectable delay paths, each pulse shaping circuit being configured to rectify and level shift a version of the globally synchronized signal through selected ones of the selectable delay paths

Abstract: Receivers (1) for receiving frequency signals are, to improve their time synchronization accuracy, provided with synchronization stages (20) for performing a coarse time synchronization through autocorrelating samples of a group of preamble symbols (t1,t2,t3) and a fine time synchronization through crosscorrelating samples of a further group of preamble symbols (t10,G1) with predefined samples. The synchronization stages (20) also perform a coarse and a fine frequency synchronization through detecting and accumulating phases of samples of a yet further group of preamble symbols (t8,t9) and of another group of preamble symbols (T1,T2). The synchronization stages (20) have buffering units (21) and controlling units (22) for controlling mixing units (11) and transformating units (12) in processing stages (10). The preamble symbols have ten short preamble symbols (t1-t10), a guard interval preamble symbol (G 1) and two training symbols (T 1,T2).

Abstract: A system and method for performing output clock phase smoothing. A phase smoothing circuit is described and includes a numerically-controlled oscillator (NCO) configured to produce a plurality of NCO clock pulses at a selectable frequency that is based on an input clock. Edges of the plurality of NCO clock pulses are aligned to edges of the input clock. A phase error calculation module is coupled to the NCO and is configured to generate a corresponding phase error for each of the plurality of NCO clock pulses. A clock phase selectable delay is coupled to the phase error calculation module and is configured to adjust each of the plurality of NCO clock pulses according to the corresponding phase error to generate an output clock at the selectable frequency that are phase-adjusted to more closely match an ideal output clock phase. Edges of the output clock need not necessarily align to the edges of the input clock.

Abstract: A training sequence is created for space-time diversity arrangement, having any training sequence length, while limiting the training sequence to a standard constellation. Given a number of channel unknowns that need to be estimated, L, a training sequence can be creates that yields minimum means squared estimation error for lengths Nt=kNPRUS+L?1, for any positive integer k?1, where NPRUS is a selected perfect roots-of-unity sequence (PRUS) of length N. The training sequence is created by concatenating k of the length N perfect roots-of-unity sequences, followed by L?1 initial symbols of that same PRUS. Good training sequences can be created for lengths Nt that cannot be obtained through the above method by concatenating a requisite number of symbols found through an exhaustive search.

Abstract: A technique for enhanced reconditioning equalizer filter for non-constant envelope signals is described. The input to a transmitter chain is modified by an enhanced reconditioning equalizer filter, prior to being applied to the transmitter. The enhanced reconditioning equalizer filter modifies and smoothens the amplitude of the signal. The modified and smoothened signal has its peaks reduced which results in lower Crest Factor. The input to the enhanced reconditioning equalizer filter could be a baseband, an intermediate frequency (IF) or radio frequency (RF) signal. When the signal is an IF or RF signal it needs to be down converted to baseband before applied to enhanced reconditioning equalizer filter. The enhanced reconditioning equalizer filter could be implemented in digital or analog domain.

Abstract: A technique for enhanced reconditioning equalizer filter chain for multi-carrier signals with different technologies is described. The input to a transmitter chain is modified by an enhanced reconditioning equalizer filter chain for multi-carrier signals with different technologies, prior to being applied to the transmitter. The enhanced reconditioning equalizer filter chain modifies and smoothen the amplitude of the signal. The new signal is reconditioned and smoothened and has lower Crest Factor. The input to the enhanced reconditioning equalizer filter chain for multi-carrier signals with different technologies could be a baseband, an intermediate frequency (IF) or radio frequency (RF) signal. When the signal is an IF or RF signal it needs to be down converted to baseband before applied to enhanced reconditioning equalizer filter chain. The enhanced reconditioning equalizer filter chain for multi-carrier signals with different technologies could be implemented in digital or analog domain.

Abstract: A digital demodulator includes a resonator having a resonance frequency same as a carrier frequency to store a charge corresponding to a digital signal modulated by phase shift keying, a capacitor to store the charge of the resonator, an amplifier including an input node and an output node between which the capacitor is connected to convert a stored charge of the capacitor into a voltage signal, and a controller configured to accumulate in the resonator the charge induced by the frequency signal modulated by phase shift keying in a first control mode and configured to transfer the charge of the resonator to the capacitor in a second control mode, to output the voltage signal corresponding to the stored charge of the capacitor from the output node of the amplifier.