Abstract: A method and apparatus for detecting an envelope are provided. The method and apparatus may detect an envelope of a modulating signal based on a low calculation complexity and a simple circuit configuration, by detecting an envelope for a plurality of sampling signals with equal time intervals.

Abstract: Apparatus having corresponding methods and non-transitory computer-readable media comprise: a transmitter configured to transmit a signal according to a gain setting, wherein the signal represents a first digital signal; a receiver configured to receive the signal transmitted by the transmitter, and produce a second digital signal based on the signal received by the receiver; a measurement module configured to produce a digital indication of a linearity of the transmitter based on the second digital signal; and a gain setting module configured to control the gain setting in accordance with the digital indication of the linearity of the transmitter.

Abstract: Preceding filters receive the inputs of a plurality of received signals associated respectively with a plurality of antennas. Subsequent filters band-limit the plurality of inputted received signals, respectively. A first combining unit derives a weight vector for the plurality of band-limited received signals and performs array synthesis on the plurality of band-limited received signals, using the derived weight vector. The second combining unit performs array synthesis on the plurality of inputted received signal signals, using the derived weight vector. A demodulator demodulates the array-synthesis result.

Abstract: A peak to average power ratio signal is generated from a first mapping function that selects the peak to average power ratio signal that corresponds to the data rate or data format of the signal to be transmitted. The selected peak to average power ratio signal is summed with a desired average transmit power signal. The resulting summation signal is input to a second effectively continuously valued mapping function comprising a table that has a plurality of power amplifier control signal values each with a corresponding peak transmit power. Each peak transmit power signal value results in a power amplifier control signal value that achieves the best possible transmitter power efficiency while still meeting out of band spurious emissions and waveform quality requirements. The summation signal value maps to one of the power amplifier control signal value that is then used to adjust a parameter such as bias of the power amplifier.

Abstract: The performance and symbol rate in a wireless mobile system are increased by forming a transmission code matrix using transformed orthogonal codes, in such a way that the code is robust to channel statistics and operates well in both Ricean and (correlated) Rayleigh channels. Furthermore, the invention enables high symbol rate transmission using multiple transmit antennas, and one or multiple receive antennas, and obtains simultaneously high diversity order and high symbol or data rate.

Abstract: A technique for encoding a signal used in a digital communication system in which individual traffic channel data rates may be adapted to specific channel conditions. In particular, a forward error correction coding rate is adapted for individual channels while at the same time maintaining a fixed block size independent of the FEC coding rate. This allows the system data rate to adapt to the channel conditions experienced by a specific user. Thus, users experiencing good communication conditions with low multipath distortion may be allocated higher capacity, whereas users with significant multipath distortion may make use of lower rate (higher levels of coding) error codes to maintain high quality. Messages are sent from a transmitter to a receiver to inform the receiver of the coding rate implemented at any given point in time.

Abstract: A system for providing voltage isolation includes the first and second chips, each containing functional circuitry. The chips are interconnected via at least one RF isolation link that provides voltage isolation between the first chip and the second chip.

Abstract: A method and receiver systems for demodulating and decoding a hierarchically modulated signal, e.g. an 8 PSK signal, are disclosed. An exemplary method includes demodulating and processing (502) the hierarchically modulated signal (202) to produce symbols (212) from the first modulation at the first hierarchical level, applying information (504) from a plurality of the symbols from the first modulation at the first hierarchical level in subtracting (214) from the demodulated hierarchically modulated signal to obtain the second modulation at the second hierarchical level and processing (506) the second modulation at the second hierarchical level to produce second symbols (222) from the demodulated second signal. The hierarchically modulated signal comprises a non-uniform 8 PSK signal. Applying the information from the plurality of the symbols from the first modulation can be achieved by applying the symbols after error correction.

Abstract: Apparatus and method for generating signal gain coefficients for use in packet data communication between a single-input-single-output (SISO) transceiver and a single-input-multiple-output/multiple-input-single-output (SIMO/MISO) transceiver. Coordinate rotation digital computation (CORDIC) techniques are used to generate transmit channel coefficients which are substantially complementary to receive channel coefficients representing relative strengths of individual signals received via multiple spatially diverse antenna elements and corresponding to a wireless data signal originating from a particular SISO radio frequency (RF) transceiver. Using such transmit channel coefficients to produce outgoing RF signals for transmission via the same antenna elements and reception by such particular SISO RF transceiver provides for signal transmission and reception diversity.

Abstract: A phase lock loop comprising a plurality of voltage controlled oscillators is presented herein. The phase lock loop can provide a wide range of output frequencies with low jitter. Additionally, the phase lock loop can be incorporated into a clock multiplier unit and a clock and data recovery unit.

Abstract: An AFC (Automatic Frequency Control) device of a QPSK modulation system including a frequency discriminating unit for calculating a real part peak value using frequency discrimination between adjacent I and Q signals of a received sequence and an imaginary part peak value using the frequency discrimination between adjacent I signals and adjacent Q signals, an error detecting unit for detecting an error symbol from the received sequence, and a switching unit for removing the detected error symbol under the control of the error detector. Also included is a frequency difference average calculating unit for calculating a frequency difference of the received sequence without the error symbol.

Abstract: The invention provides a device for reducing ingress noise in a digital signal, comprising a noise predictor for predicting an amount of ingress noise in the digital signal based on past samples of the ingress noise, and a subtractor for subtracting the predicted amount of ingress noise from the digital signal. Channel distortion is compensated for by a noise-independent equalizer, such as a ZF equalizer, placed upstream of the noise predictor. The device may be incorporated, for example, in a cable modem termination system (CMTS) of an hybrid fiber/coax (HFC) network.

Abstract: A receiver of a frequency-modulated signal is provided. The receiver includes a frequency-transposition unit for lowering the frequency of the frequency-modulated signal, and a digital demodulator for regenerating a digital signal from the frequency-transposed signal. The frequency-transposition unit includes a local oscillator for generating a local oscillator signal used in lowering the frequency of the frequency-modulated signal. The frequency-transposed signal is sampled in the digital demodulator at the rate of a sampling signal, and the sampling signal is generated by the local oscillator of the frequency-transposition unit. In a preferred embodiment, the local oscillator includes at least one frequency-divider circuit that delivers the sampling signal. Also provided is a method for regenerating a digital signal from a frequency-modulated signal.

Abstract: A method is provided for training a rake finger (200). In this method the rake finger receives a data signal including a plurality of signal components having a plurality of signal phase values, respectively. (620). The rake finger then sets a current acquisition phase for a locally-generated signal (620) and then calculates a value of an autocorrelation function for the received data signal with the locally-generated signal at the current acquisition phase. (630). The rake finger determines when the autocorrelation function is at a peak value (640), saving the peak value in a storage device (290) when the autocorrelation function is at the peak value (650). The rake finger can then set a finger weight (W) for the rake finger based on the peak value stored in the storage device. This method can be performed at least in part during an acquisition process for the rake finger.

Abstract: Methods and circuits utilizing a two stage adaptation algorithm to determine the optimal code for an equalizer to compensate a received signal is disclosed. In the first stage, a coarse tuning algorithm is used to choose a range of codes based on the amplitude of the received signal. The chosen codes will be used as reference points in the second stage. In the second stage, a fine tuning algorithm is used to select a code in the range of reference codes determined in stage one. The fine tuning algorithm looks to the status of the data lock signal generated by the clock recovery circuit. If the data lock signal does not indicate a lock, the fine tuning algorithm cycles through the range of reference codes. If the data lock signal indicates a lock, then that particular code is continued to be used for the equalizer.

Abstract: A system for providing voltage isolation includes the first and second chips, each containing functional circuitry. The chips are interconnected via at least one RF isolation link that provides voltage isolation between the first chip and the second chip and limits common mode signals therebetween.

Abstract: A system and method for synchronizing sub-carriers in a signal processing system. Various aspects of the present invention may comprise method steps and structure that receive a sampled signal. Various aspects may produce a synchronization signal based on the sampled signal. Various aspects may generate and store a cropped version of the received sampled signal. Various aspects may read a cropped sampled signal from memory that corresponds to the received sampled signal. Various aspects may generate a restored sampled signal by adding samples to the cropped sampled signal read from memory. Various aspects may, based on the synchronization signal, output the restored sampled signal coarsely synchronized to the received sampled signal. Various aspects may determine a phase difference between the output restored sampled signal and the output received sub-carrier. Various aspects may adjust the phase of the restored sampled signal in response to the determined phase difference.

Abstract: The method and device performs spread spectrum based communication and/or navigation. Device embodiments may include a receiver having a plurality of programmable tracking units and a processor in communication with the receiver to control the device, such as reconfiguration of the device from one mode to another mode. The tracking units are programmable in a navigation mode to receive and process the satellite navigation signals or in a communication mode to receive and process the spread spectrum based communication signals. When the receiver is configured to track navigation signals, operation may include acquiring the tracked navigation signals, synchronizing the tracking units, obtaining correlation data from a set of correlators, determining pseudo-ranges based on the correlation data, and determining a position fix based on the pseudo-ranges.

Abstract: Improved control apparatus and methods transfer information between devices, such as controllers and field devices, utilizing a modulator that generates a pulse width modulated (PWM) signal containing information to be transferred by a first of the devices, e.g., the controller, to the second device. A transformer or other inductive device transfers the PWM signal across the isolation barrier, where it is demodulated to analog form for application to the second device, e.g., the field device. Information transferred from the second device to the first device can be transferred in an amplitude modulated (AM) signal that utilizes, as its carrier, a fixed duty cycle output of the modulator that generates the PWM signal.

Abstract: A receiver and method are provided for receiving signals transmitted thereto from a transmitter during operation of a radio communication system. To synchronize the receiver with the transmitter, the receiver includes a delay lock loop circuit capable of receiving a pilot signal and a diversity signal transmitted from a plurality of transmit antennas and/or received by a plurality of receive antennas. The delay lock loop circuit is capable of calculating a first error signal based upon the pilot signal, and a second error signal based upon the diversity signal. The delay lock loop circuit is then capable of forming a combined error signal based upon the first and second error signals, and capable of synchronizing the receiver with the transmitter based upon the combined error signal.