Abstract: A receiver may reduce the effects of distortion when determining signal usability in the following manner. Upon receiving a signal, the receiver separates a desired component, an undesired component, and a distortion component, wherein the desired component includes the signal that was originally transmitted and the undesired component includes interference and noise. Having isolated the distortion component, it can be mitigated such that the usability of the signal received can be determined based on a ratio between the desired and undesired components.

Abstract: A receiver that receives a stream of information symbols may detect the usability of the stream of information symbols received as follows. Upon receiving the stream of information symbols, the receiver separates the stream of information symbols into a desired portion and an undesired portion wherein the desired portion is the originally transmitted stream of information symbols and the undesired portion is interference and noise. From the undesired portion and the desired portion, the usability can be determined based on a ratio of the two portions.

Abstract: A diversity receiver that receives diverse modulated signals may produce a usable signal from the received modulated signals in the following manner. Two modulated signals, each including a desired component and an undesired component, are received by the diversity receiver, wherein each desired component includes an originally transmitted signal and each undesired component includes noise and interference. The diversity receiver estimates each desired and undesired component and produces the usable signal based on the estimated desired components and the estimated undesired components.

Abstract: A receiver may reduce the effects of distortion when determining signal usability in the following manner. Upon receiving a signal, the receiver separates a desired component, an undesired component, and a distortion component, wherein the desired component includes the signal that was originally transmitted and the undesired component includes interference and noise. Having isolated the distortion component, it can be mitigated such that the usability of the signal received can be determined based on a ratio between the desired and undesired components.

Abstract: In the following manner, a receiver that receives quadrature modulated signals may determine desired components of the quadrature modulated signals by minimizing effects of transmitted distortion produced by gain, phase, or gain-phase imbalance. A quadrature modulated signal that includes a desired component, a fading component, and a transmitter distortion component is received by the receiver, wherein the transmitter distortion component includes a conjugate component and an imbalance component. The receiver estimates the fading component, the conjugate component, and the imbalance component and determines the desired component based on these estimates and the quadrature modulated signal.

Abstract: The ratio of peak power level to average power level in a power amplifier used in a QAM communication system transmitter can be reduced by preselecting magnitudes and phase angles of complex-valued pilot symbols used in multi-channel, N-level QAM.

Abstract: In order to maintain low-splatter in a peak-to-average reduction for a linear communication system, a method of windowed-clipping is used. When a sample of input signal is determined to be above a predetermined threshold, a signal peak is found and an attenuating window is centered at the peak. The attenuating window is applied to the input signal.

Abstract: In a digital communication system in which pulse-shape filtered sync, pilot, and data symbols, arranged in successive time slots, modulate sub-channel carriers via sub-channel mixers to form sub-channel symbol streams for combination into a composite signal for transmission, deterministic portions of each time slot are rendered identical by determining phase difference of sub-channel carriers and rotating the phase of each sub-channel symbol stream by an amount equal to the phase difference, but with opposite sign.

Abstract: Disclosed is a method of selecting a relatively high reliability signal path between a mobile communication unit and a number of possible base sites.

Abstract: A method for implementing diversity reception to counteract effects of channel fading on a transmitted information signal. In diversity receive paths, estimates of complex channel gain are computed based upon pilot symbols inserted from time to time in the transmitted information symbol stream. Phase corrected and weighted samples from the diversity paths are summed prior to the decision process. The squared magnitudes of the diversity path channel gains are summed to provide the proper threshold adjustment.