Abstract: A system and method is herein described for the wide band acquisition of a high performance waveform in an environment with poor signal to noise ratio. The waveform acquired has a preamble with a plurality of frequency modulated Maximum Length Sequences and a period of pure carrier. In one embodiment, method provides an application specific integrated circuit (ASIC) for receiving the waveform, filter coefficients for use with the MLS's portion of the waveform, and filter coefficients for the pure carrier portion of the signal. Another embodiment may also include, for the MLS portion of the signal, detecting the signal through partial correlation, extracting waveform information, and estimating symbol timing. Yet another embodiment may further include, for the pure carrier portion of the signal, estimating the phase and frequency of the signal and providing those estimates to an ASIC.

Abstract: A method and apparatus use unified equations to provide computationally efficient but exact solutions to bit soft value computations for Gray-coded QAM symbols in a received communication symbol as compared to carrying out region-specific equations that are keyed to particular regions of a nominal modulation constellation. Such unified equations further may include one or more correction terms that compensate the bit soft value computations for the effects on symbol samples of more than one “nearest” neighbor in the nominal modulation constellation. While the computations offer particular advantages for receivers making use of the HS-DSCHs used in WCDMA, the method and apparatus can be used in essentially any wireless receiver or system employing Gray-coded QAM.

Abstract: The present invention provides a digital spread spectrum frequency synthesizer that comprises a noise-shaped quantizer, a divider and an adjustment means. The noise-shaped quantizer is used to quantize a period control word to a time-varying value. The divider is used for generating an output signal by means of dividing a reference signal by the time-varying value, the output signal feeding back to the noise-shaped quantizer so that the noise-shaped quantizer generates the time-varying value in response to the feedback output signal. The adjustment means is used to adjust the period control word by a period offset in response to the output clock. Accordingly, the frequency synthesizer of the present invention can provide a very precise frequency synthesizer featuring a precision spread spectrum clock and jitter stability as well.

Abstract: A soft symbol decoder for use in a multiple input multiple output (MIMO) and OFDM (orthogonal frequency division multiplexing) system. The decoder generates soft symbol values for a digital signal that represents a number of source bits. The source bits are transmitted as symbols in corresponding to points in a signaling constellation. Soft metrics are determined by searching for all possible multi-dimensional symbols that could have been transmitted. The method includes transmitting a sample of the multi-dimensional symbol using K transmit antennas. The multi-dimensional symbol is represent-able as a complex, K-dimensional vector x. Each vector component of vector x represents a signal transmitted with one of the K transmit antennas. After transmission through a communication channel, a sample corresponding to the transmitted sample is received. The received sample is represented by a complex, N-dimensional vector y, where N is the number of receive antennas in the MIMO system.

Abstract: A sample-and-hold (SAH) phase detector (PD) is clocked in such a way (using a reverse clocking mode) so as to avoid quantization noise increases due to folding that is generally associated with conventional charge pump based phase detectors. The PD is clocked with a clean clock (reference clock), rather than a divided clock. The SAH PD architecture additionally includes an integrated filtering function.

Abstract: A data recovery system for a serial digital data link includes a data sampler, compare logic, a phase controller, and a phase shifter. The data sampler samples input data three times in a bit time which time is determined by clock pulses generated by the phase shifter, and recovers digital data according to a predetermined decision criterion. The compare logic compares the output of the data sampler according to a predetermined method. Phase controller uses the output of the compare logic and generates phase control signals. The phase shifter uses the phase control signals and makes three different phase clocks from input clock. The input clock can be an external clock, or can be recovered from the external clock or input data stream.

Abstract: Systems and methods are described for multicarrier orthogonal spread-spectrum (MOSS) data communication. A method includes individually spread-spectrum modulating at least two of a set of orthogonal frequency division multiplexed carriers, wherein the resulting individually spread-spectrum modulated at least two of a set of orthogonal frequency division multiplexed carriers are substantially mutually orthogonal with respect to both frequency division multiplexing and spread-spectrum modulation.

Abstract: A digital data system (100) provides 1-D, 2-D and 3-D capability and multi-band channel capability. Improved filter banks are created by generating a filter bank having an analysis portion and synthesis portion and obtaining wavelet coefficients (302) for each portion. The wavelet coefficients are expressed in a format capable of canonical signed digit (CSD) representation, such as integers (302). The canonical signed digit (CSD) representation is controlled by a value, N, selected to control resolution of the CSD coding. Optimized CSD-coded wavelet coefficients are used as filters for data signals (318).

Abstract: Two correlation signals which are obtained by computing correlations between two reference signals and a reception signal are inputted to a level-0 cell, the reference signals being generated on the basis of combinations of crosstalk coefficients. A level-1 soft judgment target signal is produced by using soft judgment target signals that are outputted by two sets of level-0 cells respectively and, similarly, a level (N+1) cell is formed by using two sets of level-N cells, whereby a soft judgment target signal creation portion with a hierarchical structure is constituted. A judgment unit outputs a soft judgment value of the target subchannel on the basis of the soft judgment target signal that is outputted by the level (N+1) cell, and judges a reception signal.

Abstract: The present invention provides a transceiver for receiving and transmitting data over a network, and a method for testing the same. In particular, the present invention provides a physical layer transceiver having a built-in-self-test (BIST) device that allows for, among other things, pulse density/width variation and jitter control.

Abstract: A system and method for establishing a known timing relationship between two clock signals, wherein a first clock signal is operable to clock data transfer operations from a transmitter domain to a receiver domain and a second clock signal is operable to be transported to the receiver domain. Circuitry is provided for detecting an edge in a global framework clock (GFC) signal that is supplied to the transmitter domain. A common alignment signal is manufactured that is based at least in part upon the GFC signal. A multiplexer and register arrangement is operable to output the second clock signal in response to the common alignment signal which is also used for gating the data transfer operations clocked by the first clock signal.

Abstract: A data recovery device. The device adjusts a digital signal according to a pulse signal output by a phase-locked loop circuit. The sampling circuit samples each bit of the digital signal five times to generate a first sampled signal. The data delay buffer decides a sampling range of the first sampled signal and outputs a second sampled signal. The sampling range selector picks a part of bits of the second sampled signal and outputs output data. The weighted detecting module outputs a phase shifting signal responding to the output data. The first loop filter outputs a first adjusting signal. The first sampling window module outputs a phase selecting signal. The second loop filter outputs the recovery signal and a second adjusting signal. The second sampling window module outputs the first phase checking signal and the second phase checking signal. The phase picking module outputs the output data.

Abstract: The present invention discloses an apparatus for initial synchronization and cell search in a CDMA system based on multipath energy window. The apparatus perform initial synchronization and adjacent cell search by using multipath energy window based on the processing method of multipath energy window. The apparatus can be implemented based on a parallel correlator bank. This invention also provides the application of the apparatus to a coherent spreading receiver.

Abstract: A method and apparatus for displaying substantially noise-free segments of serial data waveforms. The method comprises the steps of dividing an acquired waveform into a plurality of waveform slices and categorizing each of the plurality of waveform slices according to at least a sequence of N bit values prior to a bit value being observed. The waveform slices in each category are then averaged resulting in an average pattern for each category. Each of the averaged patterns is then displayed on a display in an overlayed manner.

Abstract: A method for tracking carrier frequency and sampling frequency offsets in an OFDM wireless communication system comprises: (a) detecting data received from the transmitter using a first signal, and tracking a phase offset caused by the carrier frequency offset using the detected received data; (b) detecting the data received from the transmitter using the first signal, and tracking the phase offset caused by the sampling frequency offset using the detected received data; (c) compensating for the phase offset caused by the carrier frequency offset between the transmitter and the receiver according to the phase offset tracked in (a); and (d) compensating for the phase offset caused by the sampling frequency offset between the transmitter and the receiver according to the phase offset tracked in (b).

Abstract: A dual link receiver terminates, recovers, channel aligns, and link aligns a plurality of primary link channels and a plurality of secondary link channels. The plurality of primary link channels and the plurality of secondary link channels are each received, bit recovered. synchronized, decoded and channel aligned. Then, the plurality of primary link channels and secondary link channels are link aligned. Link alignment operations first determine a relative misalignment between the plurality of primary link channels and the plurality of secondary link channels. A primary link delay is then applied to the primary link channels and a secondary link delay is then applied to the secondary link channels. A difference between the primary link delay and the secondary link delay is based upon the misalignment between the plurality of primary link channels and the plurality of secondary link channels. An enabling circuit precludes an incorrect blanking period indication.

Abstract: Provided are a method and apparatus for high-speed, multi-mode PAM symbol transmission. A multi-mode PAM output driver drives one or more symbols, the number of levels used in the PAM modulation of the one or more symbols depending on the state of a PAM mode signal. Additionally, the one or more symbols are driven at a symbol rate, the symbol rate selected in accordance with the PAM mode signal so that a data rate of the driven symbols is constant with respect to changes in the state of the PAM mode signal. Further provided are methods for determining the optimal number of PAM levels for symbol transmission and reception in a given physical environment.

Abstract: A method of detecting frequency errors in a receiver during frame synchronization. A fast synchronization and reliable reception of the data requires a fast determination of frequency errors in the received signal. In CPFSK and OFDM, the frequency offset is even more important because of potential subcarrier interference. The method operates in the time domain and removes the 2p limitation in the phase representation by an unwrap function allowing a precise frequency determination.

Abstract: A technique associated with transceiver systems solves transmitter impairments when the system has both receiver and transmitter operating with the same local oscillator frequency but with independent phase and gain impairments.

Abstract: A technique for peak suppression, phase and amplitude equalizer of multi-carrier signals with different modulation is described. The input to the multi-carrier power amplifier is modified by a peak suppression, phase and amplitude equalizer circuit prior to being applied to the amplifier. The peak suppression is applied to a multi-carrier signal with different modulations and bandwidth. After peak suppression each individual carrier is phase and amplitude equalized to maintain the properties of the multi-carrier signal. The phase equalizer maintain the timing property of the carriers and the amplitude equalizer maintain the modulation accuracy of the individual carriers. The input to the peak-to-average reduction circuit could be a baseband, an intermediate frequency (IF) or radio frequency (RF) signal. The peak-to-average reduction is performed in digital domain.