Abstract: Techniques to select an antenna from a plurality of antennae used for wireless communications are described. A first embodiment of the techniques is a method to select an antenna from a plurality of antennae. The method includes monitoring at least one antenna during a fraction of at least one preamble period of a frame to derive at least one quality indicator corresponding to the antenna; storing the quality indicator derived from monitoring the antenna during the fraction of the preamble period of a frame; and selectively switching to a selected antenna after a number of frames, based on the quality indicator. A second embodiment is another method to select an antenna from a plurality of antennae. These embodiments can be applied in several wireless communication applications using multiple antennae.

Abstract: Techniques to generate synchronization information from received signals in communication applications are disclosed. According to one embodiment, a method for generating synchronization information from received signals includes providing a fixed gain to a received analog signal to generate a modified analog signal, converting the modified analog signal to a digital signal, extracting one or more sign bits from the digital signal, and generating synchronization information as a function of the one or more sign bits. Various embodiments can be applied in several wireless and wired communication applications.

Abstract: To reduce the ISDN crosstalk in an incoming DSL signal, a crosstalk canceller observes at least a portion of the crosstalk signal and reproduces an estimate of the crosstalk signal for at least a portion of that signal within the DSL band. The crosstalk canceller applies a canceling signal based on the estimated crosstalk signal to reduce the crosstalk in the received DSL signal.

Abstract: A method and system to select an antenna from a plurality of antennae used for wireless communications. A first embodiment is a method to select an antenna from a plurality of antennae. The method includes monitoring at least one antenna during a fraction of at least one preamble period of a frame to derive at least one quality indicator corresponding to the antenna; storing the quality indicator derived from monitoring the antenna during the fraction of the preamble period of a frame; and selectively switching to a selected antenna after a number of frames, based on the quality indicator. A second embodiment is another method to select an antenna from a plurality of antennae. These embodiments can be applied in several wireless communication applications using multiple antennae including, but not limited to, WiMAX applications.

Abstract: A method and system to generate decoded information from received symbols in communication receivers. A first embodiment is a method to detect digitally modulated symbols and generate decoded information. The method includes receiving digitally modulated symbols, demapping the digitally modulated symbols to generate soft decisions representing digitally modulated symbols, multiplying the soft decisions by an adaptive factor to generate scaled soft decisions; and decoding the scaled soft decisions to generate decoded information. A second embodiment is a system having modules to detect digitally modulated symbols and generate decoded information. These embodiments can be applied in several wired and wireless communication applications including, but not limited to, WiMAX applications.

Abstract: A method and system to generate synchronization information from received signals in communication applications. A first embodiment is a method to generate synchronization information in a communications receiver. The method includes providing a fixed gain to a received analog signal to generate a modified analog signal, converting the modified analog signal to a digital signal, extracting one or more sign bits from the digital signal, and generating synchronization information as a function of the one or more sign bits. A second embodiment is a system to generate synchronization information in a communications receiver. Various embodiments can be applied in several wireless and wired communication applications including, but not limited to, WiMAX applications.

Abstract: A single ended line testing (SELT) method using a Frequency-Domain Reflectometry (FDR) that uses one or more echo signals originated by transmitting a periodic multi-tone sign, e.g., a REVERB signal, reflected from the hybrid and analyzes it in frequency domain. The REVERB signal is part of the ADSL modem training signal. Therefore the invention can be simply implemented as part of the DMT-based DSL modem because transmitting a multi-tone signal and capturing the frequency response of echo are readily available through the inverse fast Fourier transform/fast Fourier transform (IFFT/FFT) blocks that are used for modulation and demodulation.

Abstract: An echo cancellation (EC) system for use in a full-duplex communication system having asymmetric signal sampling rates, in particular an ADSL system, is described. The system performs the cancellation of local echo signal in digital or analog domain depending on the loop condition using a switching logic. The EC system further includes an EC unit that generates a digital echo estimate signal at the lower sampling rate of the transmitted signal and then interpolates the digital signal to higher sampling rate to cancel echo signal thereby reducing computation complexity. The digital interpolated echo estimate signal is converted to analog form for use in analog echo cancellation. The subtracted signal resulting from the analog echo cancellation is converted into digital domain and used as feedback for the EC unit to adaptively improve the accuracy of the echo estimate.

Abstract: A process for signal detection in EDGE cellular systems is presented with the step of wireless channel estimation, a time-reversed signal processor, a soft-output Viterbi signal detector consisting of forward and reverse block processing, a MAP decoder that exchange soft information with the equalizer. Claim 1. A signal detection mechanism to demodulate received data frame that includes an accurate estimator to obtain channel responses, a forward filter and a FIR decision feedback filter to be used in soft-output equalizer, a time-reversal device storing received data in a time-reversed order for reverse block processing, an interference removal apparatus in both forward and reverse processing blocks, and a soft-input soft-output reduced state equalizer that utilizes the forward processing and reversed time processing blocks to generate iterative soft-output signals to the forward error correction decoder within the receiver system.

Abstract: To reduce the ISDN crosstalk in an incoming DSL signal, a crosstalk canceller observes at least a portion of the crosstalk signal and reproduces an estimate of the crosstalk signal for at least a portion of that signal within the DSL band. The crosstalk canceller applies a canceling signal based on the estimated crosstalk signal to reduce the crosstalk in the received DSL signal.