Abstract: A method and apparatus are disclosed to generate and/or receive ultra-wide bandwidth (UWB) pulses using a digital clock.

Abstract: A concatenated coding scheme, using an outer coder, interleaver, and the inner coder inherent in an FQPSK signal to form a coded FQPSK signal. The inner coder is modified to enable interative decoding of the outer code.

Abstract: Described are communication systems that convey differential and common-mode signals over the same differential channel. Noise-tolerant communication schemes use low-amplitude common-mode signals that are easily rejected by differential receivers, thus allowing for very high differential data rates. Some embodiments employ the common-mode signals to transmit backchannel signals for adjusting the characteristics of the differential transmitter. Backchannel control signals are effectively conveyed even if the forward channel transmitter is so maladjusted that the received differential data is unrecognizable. Systems in accordance with the above-described embodiments obtain these advantages without additional pins or communications channels, and are compatible with both AC-coupled and DC-coupled communications channels. Data coding schemes and corresponding data recovery circuits eliminate the need for complex, high-speed CDR circuits.

Abstract: Method and apparatus for providing an amplified modulated radio frequency signal, the method comprising the steps of providing a radio frequency (RF) oscillatory signal, generating from the RF oscillatory signal and an input signal a pair of phase modulated phase conjugated signals, and summing the pair of signals to provide the desired modulated RF signal output. A form of the invention is applied to digital modulation using in-phase (I) and quadrature (Q) input signals. Each of the I and Q signals is processed in a respective channel, with the channel outputs being summed. The channels share an RF oscillatory signal, which is phase shifted by 90 degrees within the Q channel.

Abstract: A communication system is provided including a transceiver and an application controller to transmit and receive signals through the transceiver. An isolator which insulates and separates the transceiver and application controller includes primary and secondary side circuits insulated from each other on a substrate and a capacitive insulating means to transfer signals between the primary and second sides while insulating and separating the primary side circuit from the secondary side circuit.

Abstract: A method and apparatus reliably encode and decode information over a communication system. The method includes transforming two coefficients into two pairs of random variables, one random variable in each pair having substantially equal energy as one random variable in the other pair. The method further includes quantizing each of the pairs of random variables and entropy coding each quantized random variable separately creating an encoded bitstreams. The encoded bitstreams are received by a decoder which first determines which channels of the communication system are working. The encoded bitstream is entropy decoded, inversed quantized and inversed transformed. An inverse transform performs three different transformations depending upon which channels are working, i.e., whether the first, second or both channels are working.

Abstract: A method of communicating digital signal information through diversity signaling with a constrained amount of transmission energy-per-bit available Etot. The method includes steps of: measuring channel noise Nj and channel transmission loss gj on each of a first plurality of diversity channels; and transmitting the digital signal information from a first communications device on each of a second plurality J diversity channels, each with a channel energy allocation Ej responsive to the measurements of channel noise Nj and channel transmission loss gj; wherein j is an integer such that 1?j?J, and wherein the second plurality J diversity channels are selected from the first plurality of diversity channels, responsive to the measurements of channel noise Nj and channel transmission loss gj, and wherein the second plurality J diversity channels are selected responsive to the function ? ( 1 + ? ) · ( 2 + ? ) , wherein ? is a non-negative number.

Abstract: In a training operation for optimizing a multiplication coefficient for each tap of an FIR equalizer equalizing a read signal read from a recording medium, as a restricted coefficient updating vector applied for updating the multiplication coefficient for each tap of an FIR filter, a vector is utilized which is obtained by projecting, onto a plane perpendicular to a predetermined restricting conditioning vector, a coefficient updating vector determined based on an equalizer error between the output of the FIR equalizer and a reproduction output determined therefrom and a delayed input value for each tap of the FIR equalizer.

Abstract: A broadcast system has digital receiving apparatuses that imitate deteriorated reproduction that is observed in analog receiving apparatuses when a transmission path failure occurs, thus preventing the audiences, who are accustomed to the analog broadcasting, from sensing discomfort at the digital broadcasting. A transmission apparatus causes encoding units 11 and 12 to generate low- and high-quality streams based on the same contents, and transmits these streams onto a transmission path while delaying the high-quality stream. In the receiving apparatuses, a reproduction unit 25 reproduces the high-quality stream in a normal state, while packets of the low-quality stream received during a time period T until the current time are accumulated in an accumulation unit 22. If a transmission path failure occurs, a reproduction control unit 26 causes the reproduction unit 25 to reproduce, instead of the high-quality stream, the accumulated packets of the low-quality stream.

Abstract: The invention relates to a method for determining the correlation phase between a signal received at a receiver and a replica sequence. A matched filter multiplies samples (21) of the received signal with samples (22) of the replica and sums the resulting products to obtain a correlation value for a specific correlation phase. The samples of the received signal and the replica are shifted relative to each other for each correlation phase that is to be checked. In order to reduce the computational load, it is proposed that results obtained in the correlation calculations for one correlation phase are used by the matched filter also for calculations for a subsequent correlation phase. The invention relates equally to a corresponding receiver, to an electronic device comprising such a receiver, to a device cooperating with such a receiver and to a corresponding system.

Abstract: A data transmission system in which normal transmission can be performed irrespectively of the inserting orientation of a connector is provided. A transmitting device transmits to a receiving device a differential transmission signal including polarity decision data for deciding the polarity of the connector. Based on the polarity decision data included in the differential transmission signal transmitted from the transmitting device, the receiving device decides whether the polarity of the connector has been reversed or not. When it is decided that the polarity has not been reversed, the receiving device reads data from the differential transmission signal. When it is decided that the polarity has been reversed, the polarity of the differential transmission signal is reversed for data reading.

Abstract: A method, apparatus, and system for measuring a distance between two points that includes measuring a distance intermediate a first data point and a second data point in each of two dimensions and adding the absolute values of those measured distances.

Abstract: Several code detectors in parallel simultaneously examine varying overlapping segments of a data stream containing variable length codes, referred to as a data window. The data window segments directly address memory structures within each of the code detectors without any previous logic stages. Each code detector is responsible for a range of code lengths, and ignores data window bits that are not relevant to its code length range. Each code detector outputs a possible result to a layer of logic that selects the possible result of the single code detector which contains result data corresponding to a variable length code in the data window.

Abstract: An ultra wide band (UWB) pulse train generator, which includes a trigger signal controller for sequentially outputting n trigger signals for triggering generation of UWB pulse train in accordance with n bit data to be transmitted at a predetermined time period, a latch unit for loading in parallel the n bit data to be transmitted and sequentially toggling the loaded n bit data by one bit whenever the trigger signal is input from the trigger signal controller, and a pulse train generator for generating polarity pulses corresponding to a direction of an edge transition in accordance with toggling on each output signal of the latch unit.

Abstract: A method and apparatus for compensating I/Q imbalance in receivers is described. The method includes determining a difference between energies of two quadratures, correcting an amplitude imbalance using the difference between the energies of two quadratures, determining a cross-correlation between the two quadratures, and correcting a phase imbalance using the cross-correlation between the two quadratures.

Abstract: A nonlinear distortion compensating device splits its operation into two processes. One is a compensation & amplification process for providing a receipt signal with a distortion compensating calculation and amplification before outputting the signal with phase and amplitude compensated. The other is an environmentally adapting process for modulating the signal demodulated from the input signal. Then in this process, a distortion estimating updater estimates a distortion amount using the modulated signal and a feed back signal of parts of the output supplied from the distortion compensating calculator, and updates a distortion compensating coefficient stored in the distortion compensating calculator.

Abstract: When a plurality of sub-processors are daisy chained in a loop, for example, to a main processor by a one-way bus, a command packet from the main processor addressed to itself is transmitted to the one-way bus which form a return path back to the main processor so as to easily specify a fault portion. If the command packet is returned to the main processor within a predetermined time, it is determined that no fault exists within the electronic device. When a fault exists, a test signal is transmitted to sub-processors via a dedicated signal line, separate from the one-way bus, to trigger a test packet that will be routed through the one way bus. The faulty portion in the electronic device is specified based on whether the test packet transmitted via the one-way bus in accordance with the test packet from each sub-processor is received within a predetermined time.

Abstract: Conventional receiver architectures are based on either frequency/phase tracking or oversampling. Both receiver types typically employ sensitive analog circuits, which create noise, consume power and utilize valuable space in their implementation. The invention adopts a novel approach to phase/frequency tracking that utilizes the edges or zero crossings of the input data waveform to effectively track the remote transmitter clock phase/frequency. This methodology minimizes the use of analog circuitry, thereby reducing the noise domain and the substrate space required for implementation of a tracking device.

Abstract: A spreading-code synchronization detection method for a spectrum spreading signal that increases the sensitivity of spreading-code synchronization detection and in which a spreading-code synchronization detection is applied to a spectrum spreading signal obtained by spectrum-spreading data, having a bit transition period equal to a multiple of one period of a spreading code, with the spreading code. A process for obtaining a linear-addition correlation-calculation result equal to a value obtained by linear additions of the results of correlation calculations between the spectrum spreading signal and the spreading code is performed every unit period, which is a multiple of one period of the spreading code and shorter than the bit transition period. The absolute value of the linear-addition correlation-calculation result obtained every unit period is calculated. The absolute value of the linear-addition correlation-calculation result obtained every unit period is added for a plurality of unit periods.

Abstract: A matched filter takes a correlation between a plurality of multiplexed spread spectrum signals and a spreading code. A cyclic integrator integrates a correlation waveform, associated integration outputs with phases, and sets up a maximum detection when an integration value corresponding to a predetermined phase is detected as a maximum. A correlation peak canceller regards an integration value of a phase having the maximum detection flag as a maximum of the correlation waveform of the spreading code, generates a replica signal, and eliminates the replica signal from an output of the integration. A maximum detection unit detects a maximum in a predetermined integration period and a phase corresponding to the maximum from the output of the integration after eliminating the replica signal.