A signal-of-interest is received by using a first and second planar electrically conductive disc to define an antenna. The antenna produces RF signal outputs at three output ports E.sub.x, E.sub.y and E.sub.z, each having a different associated gain pattern and polarization response. At least one null is automatically asserted in a pattern defined by the antenna in a specified direction by selectively weighting a gain and a phase of the RF signals respectively produced from the three output ports and then combining the RF signals to produce a first receiver signal output.

Various techniques are provided for a method that may include generating an additional frequency shift for wireless transmission, generating a frequency shift pattern based on a standard carrier frequency and the additional frequency shift, communicating, by a base station to a user equipment, information related to the additional frequency shift, and communicating, by the base station to the user equipment, a data stream using the frequency shift pattern.

Anti-jamming techniques are provided for RF receivers, such as those that operate in hostile environments. In some embodiments, the techniques are embodied in an anti-jam communications system configured with automatic gain control (AGC) that is complementary. The system includes a first AGC circuit prior to an interference suppression circuit and a second AGC circuit after the interference suppression circuit. The first AGC circuit operates to adjust the power level presented to the interference suppression circuit to facilitate interference cancellation. The second AGC circuit operates to maintain the original power level of the desired communications signal and prevent amplitude errors as the first AGC circuit responds to fluctuations in jammer signal power. The second AGC can be slaved to the first AGC circuit such that the sum of two gain values is held constant, according to some embodiments. In this manner, the first and second AGC circuits provide a complementary-AGC system.

A method for suppressing a spurious signal in a payload signal supplied by a receiving antenna of a payload of a satellite. The satellite also includes an array of measurement antennas supplying measurement signals. The measurement signals are combined with the payload signal. Reference weighting coefficients for weighting the measurement signals are determined as a function of the combined signals. A reference beam is formed by combining the measurement signals weighted based on the reference weighting coefficients. Anti jamming weighting coefficients for weighting the payload signal and the reference beam are determined. An anti jammed beam is formed by combining the payload signal and the reference beam weighed based on the corresponding anti jamming weighting coefficients.

Anti-jamming techniques are provided for RF receivers, such as those that operate in hostile environments. In some embodiments, the techniques are embodied in an anti-jam communications system configured with automatic gain control (AGC) that is complementary. The system includes a first AGC circuit prior to an interference suppression circuit and a second AGC circuit after the interference suppression circuit. The first AGC circuit operates to adjust the power level presented to the interference suppression circuit to facilitate interference cancellation. The second AGC circuit operates to maintain the original power level of the desired communications signal and prevent amplitude errors as the first AGC circuit responds to fluctuations in jammer signal power. The second AGC can be slaved to the first AGC circuit such that the sum of two gain values is held constant, according to some embodiments. In this manner, the first and second AGC circuits provide a complementary-AGC system.

Disclosed are methods, systems and devices for addressing a jammer signal transmitted by a device that effects a signal received at a receiver. In a particular embodiment, an application content signal is encoded for transmission in a wireless transmission medium to provide symbol content where the symbol content comprises at least some symbols representing the application content signal. A receiver may be selectively blanked synchronized with at least a portion of the symbol content.

A transmitter, including a signal processor programmed to generate, based on input serial data, for each of an integer number of subcarriers mutually orthogonal to each other, a respective first parallel data stream. The signal processor is further programmed to modulate each of the integer number of subcarriers respectively with the respective parallel stream to generate the integer number of data-modulated subcarriers. The signal processor is further programmed to modulate a single carrier occupying a same bandwidth as the integer number of subcarriers with a unique word and one or more pilot symbols to generate a second signal. The signal processor combines the first signal and second signal to generate a third signal. The signal processor generates an output signal by applying a transmit filter to the third signal.

Wide band adaptive beam forming methods and systems are provided. The beam forming methods can include receiving signals at multiple antenna elements and digitizing samples of the received signals for some period of time. The samples are divided into sub-channels according to frequency, and interferers are identified as signals appearing across at least some minimum number of the sub-channels. After removing signals not identified as interferers from the collected signal information, that information is used to calculate weights for forming a beam having a null at the identified location of the interferer. The beam forming systems include multiple element antennas having arms in the form of a spiral, and processing hardware for performing adaptive beam forming.

A radio frequency (RF) receiver, for example a satellite positioning system receiver, can be configured to use a single phase locked loop for generating an oscillator signal to perform downconversion of signals in two different frequency bands using two or more local oscillators. A first RF signal portion includes a first signal band and undergoes double downconversion using a first mixer and a second mixer, while a second RF signal portion includes a second signal band and undergoes single downconversion using a single mixer. A controller is configured to determine a first oscillator divider value and a second oscillator divider value to avoid a jammer frequency and frequency dividers are used to generate the two or more local oscillators.

A receiver includes multi-user detection (MUD) functionality and a cognitive engine. The receiver may also be coupled to multiple antennas and have analog beamforming capability. The cognitive engine is operative for selecting a beam or beams associated with the multiple antennas to enable successful demodulation by the MUD. The receiver has application in multiple access channels and in other communication scenarios.