Abstract: Timing jitter sequences ??j[n] and ??k[n] of respective clock signals under measurement xj(t) and xk(t) are estimated, and a timing difference sequence between those timing jitter sequences is calculated. In addition, initial phase angles ?0j and ?0k of linear instantaneous phases of the xj(t) and xk(t) are estimated, respectively. A sum of a difference between those initial angles and the timing difference sequence is calculated to obtain a clock skew sequence between the xj(t) and xk(t).

Abstract: In a method for setting up a communication connection between radio communication devices which carry out data communications by using a frequency hopping scheme, the first radio communication device predicts a time at which a receiving processing of an identification packet containing an identifier for uniquely identifying the second radio communication device becomes possible at the second radio communication device, and transmits the identification packet to the second radio communication device, at the time at which the receiving processing of the identification packet becomes possible at the second radio communication device, in order to synchronize a frequency hopping pattern between the first radio communication device and the second radio communication device.

Abstract: A decision feedback equalizer with dynamic feedback control for use in an adaptive signal equalizer. Timing within the decision feedback loop is dynamically controlled to optimize recovery of the data signal by the output signal slicer.

Abstract: The invention relates to a reception device implementing at least two reception paths supplied with data flows, each conveying the same source symbols, each of said paths comprising estimation means, associating, with each source symbol received, an estimated path value and a corresponding path confidence information element, and comprising means for the combination of said estimated path values into an adapted estimated value, said combination taking account of said path confidence information elements to weight said estimated path values. Said estimation means advantageously comprises means for the estimation of the transmission channel, delivering said path confidence information elements. Said combination means may advantageously associate an adapted confidence information element with each of said adapted estimated values, as a function of said path confidence information elements.

Abstract: Methods and apparatus for use in generating data sequences for direct sequence spread spectrum (DSSS) communications are described. One exemplary method includes the steps of serially generating a pseudo random noise (PN) sequence by, for each count value i of a plurality of count values, retrieving from memory a bit of the PN sequence corresponding to the (i)th position in the PN sequence. The exemplary method includes the further steps of serially generating a Gold code sequence by, for each count value i of the plurality of count values, retrieving from memory a bit of the PN sequence corresponding to the (i+n)th position in the PN sequence, retrieving from memory a bit of the PN sequence corresponding to the (q*i)th position in the PN sequence, and adding the bit corresponding to the (i+n)th position with the bit corresponding to the (q*i)th position.

Abstract: Providing clock signals includes receiving a first clock signal at a first clock circuit and at a second clock circuit, where the first clock signal comprises first cycles. A second clock signal is generated from the first clock signal at the first clock circuit, where the second clock signal comprises second cycles and a first cycle corresponds to a first multiple of the second cycles. A third clock signal is generated from the first clock signal at the second clock circuit, where the third clock signal comprises third cycles and a second cycle corresponds to a second multiple of the third cycles. The first clock signal and the second clock signal are sampled using the third clock signal. A safe cycle is determined in response to the sampled clock signals. Data is transferred in accordance with the safe cycle.

Abstract: Signals are developed for use in a wireless system with multiple transmit and multiple receive antennas so that even in the face of some correlation the most open-loop capacity that can be achieved using a substantially open-loop system with a channel of that level of correlation is obtained. In accordance with the principles of the invention, the signals transmitted from the various antennas are processed so as to improve their ability to convey the maximum amount of information. More specifically, the data to be transmitted is divided into M+1 substreams, where M is the number of transmit antennas. Each transmit antenna is supplied with a combination signal that is made up of a weighted version of a common one of the substreams and a weighted version of a respective one of the substreams that is supplied uniquely for that antenna, so that there are M transmit signals. A receiver having N antennas receives the M transmit signals as combined by the channel and reconstitutes the original data therefrom.

Abstract: The present invention uses at least one amplitude bit to assist the phase-sampling technique used in digital receiver architectures. For digital receivers where the Intermediate Frequency (IF) is an integer multiple of the fundamental frequency fo, the present invention provides reduced processing complexity and reduced power consumption. The present invention allows the digital receiver to avoid performing coordinate rotation at high speeds, and replaces such a coordinate rotation with a simple phase subtraction. This replacement of the coordinate rotation allows the receiver to use a less complicated design, and to consume less power as a result.

Abstract: The present invention provides a method and apparatus for selectively updating an adaptive element in a communications receiver based on a determination that the received data is accurate. When inaccurate data is received, the system determines that using that data to update the adaptive element will not be beneficial and excludes the data from being sent to the adaptive element. One mechanism for determining that data has been incorrectly received is the calculation of syndromes as part of a Forward Error Control (FEC) system. Detection of errors through use of the syndrome calculation can be supplemented through windowing to make a determination as to whether a number of received bits should be used or disregarded by the adaptive element. The adaptive element can comprise any number of decision-directed loops including adaptive processors and carrier and timing recovery loops.

Abstract: In a controller device, when a first transmitting signal is at a “L” level, a first operation voltage is high and the amplitude of signals CK and ICK is large, and on the contrary, the amplitude is small when the first transmitting signal is at a “H” level. In a data carrier device, the signals CK and ICK are subjected to full-wave rectification by a rectifier circuit so as to generate a second operation voltage, and a first receiving signal is extracted from the second operation voltage by a first signal detection circuit. On the other hand, in the data carrier device, when a second transmitting signal is at a “L” level, impedance between two contacts is small and the amplitude of the signals CK and ICK is small, and on the contrary, the amplitude is large when the second transmitting signal is at a “H” level. In the controller device, change of the amplitude of the signal ICK is extracted as a second receiving signal by a second signal detection circuit.

Abstract: In a noise canceling method and an apparatus therefor which notices the colored noise looked macroscopically, positively cancels the dominant noise component in the low frequency band, shifts the S/N value to plus, and can extract the reception signal buried in the low frequency band and having a comparatively high level, a signal in which a time axis, an amplitude, and a phase are specified or a zero-point signal is inserted into a transmission signal by an inserter, a noise component is interpolated by using the specified signal or the zero-point signal by a noise canceler, and an originally transmitted signal is regenerated by subtracting the noise component from the reception signal.

Abstract: Spread Spectrum baseband signals, in-phase and quadrature-phase cross-correlated baseband signals and other filtered baseband signals connected to modulators for providing modulated signals. Modulator selection for modulated signal selection or for multiple modulated signals provided to one or more antennas for signal transmission.

Abstract: A method for determining a boundary of an information element, in which a repetition coded signal transmitted by satellites is received, which signal is modulated with information elements. A group of symbols forms one information element. A group of reference values are formed on the basis of the received signal. Of these reference values at least one vector is formed wherein the number of the elements corresponds to the number of symbols use in the transmission of the information element. A determination vector is formed on the basis of the at least one vector, whereafter the greatest of the elements of the determination vector is searched. The index of said elements indicates the boundary of the information element.

Abstract: A tracking apparatus identifies distorted output signals from a digital system caused by at least one distorted signal input to the digital system. A first signal is input to the tracking apparatus when a distorted signal is input to the digital system. A second signal is input to the tracking apparatus when a non-distorted signal is input to the digital system. The tracking apparatus models a delay and widening characteristics of the digital system and operates in parallel with the digital system.

Abstract: The present invention discloses methods, apparatuses, and systems for eliminating auto- and cross-correlation in weak signal CDMA systems, such as GPS systems. The invention uses parallel data paths that allow standard correlation of signals in parallel with verification of the lock signal to determine whether the system has locked onto the proper signal within the scanned signal window. The invention can be made with multiple CPUs, a single CPU with dual input modes, on multiple IC chips, or as a single IC chip solution for small, low cost reception, downconversion, correlation, and verification systems.

Abstract: An RF receiver operates to receive broadcast RF signals that include at least one of an analog portion and a digital portion. The RF receiver performs processing of the analog portion and/or the digital portion to generate a digital path signal. The RF receiver performs further processing of the analog portion to generate a first audio signal. A digital modulation processing system may be electrically connected with the RF receiver. The digital modulation processing system may receive and process the digital path signal to generate a second audio signal. The RF receiver may selectively utilize at least one of the first audio signal and the second audio signal to generate an audio output.

Abstract: A communication device using orthogonal multiplexing carrier method for determining delay information of received radio waves. In this device, a known signal demodulator performs OFDM demodulation to output demodulated signal, and a divider performs a complex division of the demodulated signal with a data sector of known signal of a database for each sub-carrier. By the data section of the known signal, the computation result of the amount of shift can be determined for each of sub-carriers. A delay analytical calculation circuit uses the computation result of the amount of shift for sub-carriers to analyze the delayed waves. For delay analysis, ESPRIT method is used to determine delay information by means of computation result of the amount of shift for each sub-carrier.

Abstract: Based on the MAP criterion, a category of optimal timing estimators is disclosed. These estimators work with known or unknown channel information, and with received information bits over frequency-selective, slowly fading channels. A sub-optimal timing estimator with a k-taps, multiplication-free, finite impulse response (FIR) filter is also disclosed, where k equals 22 when the Barker sequence of length 11 is employed. The sub-optimal estimator is robust with respect to frequency offset impairment. Using simulations, the disclosed timing estimators are demonstrated to be effective. However, in the special case of timing estimation without channel information, in a multi-path channel with a long delay spread, it is disclosed that it is more effective to estimate the received carrier phases and amplitudes of multi-paths before timing estimation.

Abstract: Spread spectrum receiver with correlating coprocessor having common datapath for received signal correlations and code cross-correlations for efficient interference cancellation methods.

Abstract: A system and method for reducing peak-to-average ratio (PAR) values in signal transmission systems is presented. The presented approach divides a plurality of symbols into a number of non-overlapping subsets of symbols, and manipulates each of the non-overlapping subsets of symbols to produce a plurality of sub-sequences. A strategic manipulation of the subsets of symbols results in the reduction of PAR values.