Abstract: A reception level measuring system in which a base station in a code division multiple access (CDMA) mobile communication system measures a reception level of a signal from a mobile station. The reception level measuring system has an approximate-line estimating device, a phase-rotation estimating device; a Doppler-frequency estimating device and a reception signal power estimating device. The approximate-line estimating device provides an approximate line by linearly approximating signal amplitudes of a demodulated data stream in I- and Q-channels from a reception signal, in a time interval which is set in accordance with an estimated Doppler frequency. The phase-rotation estimating device estimates an amount of phase rotation based on a gradient of the approximated line. The Doppler-frequency estimating device estimates the estimated Doppler frequency based on the amount of phase rotation; and the reception signal power estimating device estimates a reception signal power based on said approximate line.

Abstract: A transceiver circuit having 10 mb and 100 mb transmit and receive circuitries using the power saving methods allows for power consumption of the transceiver circuit to be significantly reduced. This is accomplished by providing each defined subcircuit with its own power supply and means of activation and deactivation. However, the method for activating and deactivating digital subcircuits and analog subcircuits are different and therefore different types of control signals and methods are provided. Furthermore, there are two general types of power-saving situations. The first type is near total circuit power-down and the second type is partial circuit power-down. In yet another embodiment, a method for minimizing energy usage during the idle period is utilized.

Abstract: A system and method for fast synchronization of an incoming signal with a UWB receiver rapidly. The present invention synchronizes with a UWB receiver with an incoming signal. The present invention correlates a local pulse generated at the receiver with the incoming signal, finds a phase angle in the correlation function that would correspond to a high signal to noise ratio, thereby matching the receiver to the incoming signal phase, and operates the receiver at that phase. Exemplary options of fast synchronization include using multiple detection arms to compare one parameter of the correlation function to a predetermined threshold.

Abstract: In a multi-carrier system employing OFDM, for example DMT, an adaptive channel equalizer is normally used, operating in the frequency domain. The sampling clock is controlled so that the time delay between the transmitter and the receiver is effectively eliminated. If the information used to control the sampling clock is received from the equalized data stream, it will introduce an ambiguity between the operation of the channel equalizer and the mechanism used to control the sampling clock. Operation of the equalizer can mask an increasing time difference, between transmitter and receiver, which the sample clock controller should be tracking. The present invention eliminates the ambiguities in the operation of the equalizer and sample clock controller by preventing the equalizer from accepting time differences which should be corrected by operation of the sample clock controller.

Abstract: A system and method for establishing and maintaining node clock synchronization in a wireless network. The system and method calculates the clock shift, clock drift and propagation delay values using a series of message exchanges and control algorithms between a selected reference node and a client node in a wireless network, then uses these values to synchronize the client node clock to the reference node clock.

Abstract: Decoders process a digital input word to derive thermometer-coded signals for controlling one cell of an array of cells, commencing operation at the rising edge of a first clock signal. Each cell has a first latch clocked by a second clock signal, delayed by a preselected delay time ?1 relative to the first clock signal, and a second, transparent latch clocked by a third clock signal whose rising edge coincides with the rising edge of the first clock signal and whose falling edge coincides with the rising edge of the second clock signal. The rising edge of the third clock signal is not affected by jitter associated with a delay element used to delay the first clock signal by ?1. The falling edge is affected by such jitter, but is prevented from feeding through to final outputs because the second latch is non-transparent at that falling edge.

Abstract: A receiver and method for weight detection use received channel estimations and prior feedback information sent to a transmitter to estimate channel weights. The estimated channel weights may have been used by a base station to transmit diversity mode signals. In one embodiment, a trellis algorithm may be used to determine weights with no significant time-slot delay. The weights may be used to generate channel taps for use by a rake receiver in combining multipath components of received signals. In one embodiment, the receiver and method for weight detection may be suitable for use in closed loop diversity mode communication systems, including a Wideband Code Division Multiple Access (WCDMA) system.

Abstract: An adaptive equalizer with a large data rate range is provided. The equalizer comprises an equalizer core, a slicer and an automatic gain control (AGC) loop. The equalizer core is coupled to an input signal from a transmission medium and applies a transfer function to the input signal to compensate for losses incurred in the transmission medium in order to generate a core output signal. The equalizer core is also coupled to a bandwidth control signal that controls a bandwidth of the transfer function. The slicer is coupled to the core output signal and converts the core output signal to a digital output signal having a fixed digital output swing that approximates a transmission swing of the input signal prior to transmission over the transmission medium. The AGC loop is coupled to the core output signal and the digital output signal and compares the core output signal with the digital output signal in order to generate the bandwidth control signal.

Abstract: A method and apparatus provide efficient synchronization recovery at the receiver end for a digital transmission system. At the receiving end, a digital signal is received including a transmitted data portion and a guard period. A signal envelope for the received digital signal is determined, and the signal envelope is filtered to find the center of the guard period, which provides a time reference for the received digital signal. Embodiments of the present invention described herein may be used for optimal operation of a digital transmission system by efficiently recovering synchronization from a received digital signal during noisy conditions without being dependent on signal shape or requiring complicated threshold calculations.

Abstract: A Walsh code assigning apparatus includes a retaining unit retaining assignment order information about an order of assignment of the plural Walsh codes such that one Walsh code having a smaller bit length becomes unable to he orthogonally separated as being precedent over another Walsh code having a larger bit length and a controller including a retrieving unit retrieving an idle Walsh code having an assignment request bit length in accordance with the assignment order information retained in the retaining unit, and assigning unit assigning the idle Walsh code, which has been obtained by the retrieving unit, to the spreading code of a last-named communication channel for which the assignment request is issued.

Abstract: A graphametric equalizer has graphic and parametric equalization capabilities within a single non-redundant system. A translation function capability converts user selected inputs for center frequency, bandwidth and gain into allpass filter parameters to realize an allpass filter-based equalization filter structure capable of performing graphic and/or parametric equalization on-the-fly. The graphametric equalizer has a softening function capability to time user inputs and increment filter parameters gracefully such that the graphametric equalizer can be recharacterized with new filter parameters on-the-fly without incurring undesirable audible artifacts.

Abstract: A receiver includes a detector and a decoder. The detector is adapted to demodulate a received signal to generate a received word. The received word includes a plurality of symbols, and each symbol contains data associated with a first phase and data associated with a second phase. The detector is further adapted to generate a plurality of energy values relating each received symbol to one of a plurality of potential symbols. The decoder is adapted to generate a first set of bit metrics based on the energy values in response to the receiver being assigned to the first phase and a second set of bit metrics based on the energy values in response to the receiver being assigned to the second phase. The decoder is further adapted to identify the least reliable bits in the received word based on one of the first and second sets of bit metrics.

Abstract: A digital transmission line tap circuit is provided for applying a non-intrusive tap on a digital transmission line thus allowing the transmission signal to be monitored or utilized by another piece of transmission equipment. The tap circuit incorporates all the required functions of the tap in one circuit and eliminates large components, such as termination transformers.

Abstract: In a communications system having a modem pool for communicating via a communications channel, the modem pool including a plurality of modems and having a plurality A of NEXT cancellation filters, a) measuring NEXT impairment caused to at least one target modem among the plurality of modems by at least one disturber modem among the plurality of modems, b) allocating P filters among the A filters as probe filters, where P>=1, c) allocating at least one of the remaining A?P filters among the filters to cancel NEXT from at least one disturber modem among the plurality of modems, and d) measuring, using at least one of the P probe filters, NEXT impairment caused to at least one target modem among the plurality of modems by at least one candidate disturber modem among the plurality of modems to which no A?P filter is currently allocated.

Abstract: A synchronization establishing and tracking circuit for a CDMA base station is composed of a first spreading code generator, a first correlator, a second spreading code generator, a second correlator, and a phase determining circuit. The first spreading code generator generates a first spreading code sequence. The first correlator calculates first correlation between the first spreading code sequence and a first quasi-coherent signal corresponding to a first received signal received by the CDMA base station. The second spreading code generator generates a second spreading code sequence. The second correlator calculates second correlation between the second spreading code sequence and a second quasi-coherent signal corresponding to a second received signal received by the CDMA base station. The phase determining circuit determines a first phase of the first spreading code sequence based on an added quasi-coherent signal to which the first and second quasi-coherent signals are added.

Abstract: A communications system includes a first and second communication unit coupled together via a radio communications link. In one embodiment, the communications system takes the form of a frequency hopped, spread spectrum digital cordless telephone, where the first unit is a base unit and the second unit is the remote unit. The first and second communication units are respectively set to transmit and receive communication over a first radio frequency during a first time frame, select a second radio frequency during the first time frame, and set to respectively receive and transmit communication over the second radio frequency during a second time frame.

Abstract: A demodulator for demodulating digital data includes a receiver for receiving a digital data signal, a determining device to determine if a fractional sample delay added to a demodulator's symbol sampling timing would improve synchronization timing, an implementing device implementing the fractional sample delay if the determining device determines that a fractional sample delay would improve the demodulation synchronization timing, and a demodulating device for demodulating the digital data signal. A method for demodulating digital data includes the steps of receiving a digital data signal, determining if a fractional sample delay added to a demodulator's symbol sampling timing would improve synchronization timing, implementing the fractional sample delay if it is determined in the determining step that a fractional sample delay would improve the demodulation synchronization timing, and demodulating the digital data signal.

Abstract: The aim of the invention is to process OFDM signals which are simultaneously received via a multiple antenna system having a plurality of separate receive channels. To this end, the channel correction values or the confidence values are determined in the receive channels for each carrier of the OFDM signal while using known techniques. In addition, the I/Q values of each individual carrier of the OFDM signal which are obtained in the OFDM demodulator are weighted with these channel correction values or confidence values. Afterwards, the I/Q values weighted in such a manner are totaled.

Abstract: A method for managing a code sequence according to a first embodiment of the present invention is disclosed. Sets of n contiguous sample values that include sample values in a plurality of sample sequences are accessed. Sets of n contiguous coefficients are accessed. The sample values in each of the plurality of sets of sample values that are accessed are processed in parallel with corresponding coefficients that are accessed. Each of the plurality of sets of sample values are processed during a different time step.

Abstract: A fractional multi-modulus prescaler is disclosed wherein the output of the VCO is separated into four signals 90 degrees phase-related to one another. The phase signals are selected by a multiplexer for application of a division function during the modulus time period. The multiplexer is returned to the original selected phase prior to responding to a subsequent phase select control signal, whereby the generation of multi-modulus spurious frequency signals is prevented.