Abstract: Systems and methods for evaluating link performance over a multitude of frequencies for Signal-to-Noise Ratio (SNR) optimization and mitigating interference. The methods comprise: communicating, from a first communication device, a first signal over a given channel in a given frequency band; receiving, by the first communication device, spectral power measurements and a Signal-to-Total Power Ratio (STPR) estimate determined based on a second signal including the first signal combined with at least one of noise and one or more interference signals (the STPR estimate accounts for the receiver performance including chip rate processing gain and/or the performance of an interference cancellation circuit used to remove the interference signals from the second signal); and determining, by the first communication device, a predicted Signal-to-Noise Ratio (SNR) condition for a plurality of frequencies within the given frequency band using the STPR estimate and the spectral power measurements.

Abstract: Systems and methods for evaluating link performance over a multitude of frequencies for Signal-to-Noise Ratio (SNR) optimization and mitigating interference. The methods comprise: communicating, from a first communication device, a first signal over a given channel in a given frequency band; receiving, by the first communication device, spectral power measurements and a Signal-to-Total Power Ratio (STPR) estimate determined based on a second signal including the first signal combined with at least one of noise and one or more interference signals (the STPR estimate accounts for the receiver performance including chip rate processing gain and/or the performance of an interference cancellation circuit used to remove the interference signals from the second signal); and determining, by the first communication device, a predicted Signal-to-Noise Ratio (SNR) condition for a plurality of frequencies within the given frequency band using the STPR estimate and the spectral power measurements.

Abstract: Suppressing interference in a frequency hopping signal. The method includes receiving a frequency hopping signal for a signal of interest. The frequency hopping signal includes the signal of interest modulated using frequency hopping and wideband and narrowband interference. Prior to de-hopping the frequency hopping signal, one or more wideband interferences in the frequency hopping signal are identified. The one or more wideband interferences are suppressed to create a wideband interference suppressed signal. Subsequent to suppressing the one or more wideband interferences, the wideband interference suppressed signal is de-hopped to create a de-hopped signal. In the de-hopped signal, one or more narrowband interferences are identified. The one or more narrowband interferences are suppressed to create an interference suppressed signal. The interference suppressed signal is demodulated to create a demodulated signal.

Abstract: Suppressing interference in a frequency hopping signal. The method includes receiving a frequency hopping signal for a signal of interest. The frequency hopping signal includes the signal of interest modulated using frequency hopping and wideband and narrowband interference. Prior to de-hopping the frequency hopping signal, one or more wideband interferences in the frequency hopping signal are identified. The one or more wideband interferences are suppressed to create a wideband interference suppressed signal. Subsequent to suppressing the one or more wideband interferences, the wideband interference suppressed signal is de-hopped to create a de-hopped signal. In the de-hopped signal, one or more narrowband interferences are identified. The one or more narrowband interferences are suppressed to create an interference suppressed signal. The interference suppressed signal is demodulated to create a demodulated signal.

Abstract: An angle of arrival system is configured to efficiently measure phase differences. The angle of arrival system includes a master receiver for demodulating the signal received at one antenna and for implementing a tracking loop to identify the timing of symbols within the signal. This timing information can be fed back as a synchronization signal to a despreader in the master receiver and to a despreader in each of a number of slave receivers to synchronize the timing at which each signal is despread. Because despreading is synchronized, the outputs of the despreaders can be used to directly calculate phase differences between each pair of signals. In this way, the slave receivers do not need to implement a demodulator or a tracking loop. When the received signal is a non-spread signal, the phase differences between each pair of signals can be calculated directly from the modulated samples of each pair of signals without despreading.

Abstract: An angle of arrival system is configured to efficiently measure phase differences. The angle of arrival system includes a master receiver for demodulating the signal received at one antenna and for implementing a tracking loop to identify the timing of symbols within the signal. This timing information can be fed back as a synchronization signal to a despreader in the master receiver and to a despreader in each of a number of slave receivers to synchronize the timing at which each signal is despread. Because despreading is synchronized, the outputs of the despreaders can be used to directly calculate phase differences between each pair of signals. In this way, the slave receivers do not need to implement a demodulator or a tracking loop. When the received signal is a non-spread signal, the phase differences between each pair of signals can be calculated directly from the modulated samples of each pair of signals without despreading.

Abstract: The present invention, generally speaking, provides a method of obtaining very accurate estimates of the phase and amplitude distortions introduced by radio frequency or microwave power amplifiers even where polar modulation is used.

Abstract: An apparatus and method are provided for attenuating an undesired frequency (f1) relative to a desired frequency (f0) in a signal transmitted from an out-put (220) of an active element (210). Generally, the apparatus includes a parallel-resonant trap (145) coupled to the output of the active element (210), the trap including a network of reactive elements (235).

Abstract: The present invention, generally speaking, provides a method of obtaining very accurate estimates of the phase and amplitude distortions introduced by radio frequency or microwave power amplifiers even where polar modulation is used.

Abstract: A digital signal processing device and method for vestigial sideband (VSB) modulation of a digital signal. A 2.sup.n -ary digital signal d.sub.i is provided to a baseband shaping filter which samples the signal to provide a baseband signal which has real and imaginary portions Re(S.sub.bb (kT)) and Im(S.sub.bb (kT)), where ##EQU1## The VSB signal is provided with perfect sideband suppression without using analog filters. The digital signal processing device and method is characterized by requiring minimal bandwidth in the shaping filter.

Abstract: Spurious frequency components from the output signal of a direct digital synthesizer are reduced with minimum degradation of the fundamental frequency of the output signal. The synthesizer has a phase accumulator for receiving digital multibit modulation data words from a source, a periodic wave function converter for converting the modulation data words into digital waveform data words and a digital-to-analog converter for converting the digital waveform data words into an analog signal which serves as the output signal. The output signal has a frequency and waveform dictated by the modulation data words. Reduction of spurious frequency components is achieved by generating a dither waveform representing a band limited waveform. The dither waveform is summed with the modulation data words prior to application to the wave function converter to provide a dither modulated analog output signal.