Abstract: Various aspects and embodiments of the present invention derive statistics of received signal quality and use these statistics to jointly control operation of timing recovery, carrier recovery, automatic gain control, and equalization functions.

Abstract: A broadband, high-gain, active antenna system is disclosed, which operates with a bi-directive reception pattern while in its standard configuration and with a directive reception pattern over several octaves of Radio Frequency (RF) spectrum when affixed with a tuned scatter-plate. As a standalone active antenna system the disclosed antenna probe element and the amplifier subassembly exhibit the bi-directional directive properties of a standard fixed length dipole, while the addition of a scatter-plate makes the antenna directive with separate frequency-dependant directive modes. The scatter-plate can be tuned such that these separate directive modes occur at convenient areas of the RF frequency spectrum. Other means of achieving directivity are disclosed using the antenna probe element and the amplifier subassembly.

Abstract: Various aspects and embodiments of the present invention derive statistics of received signal quality and use these statistics to jointly control operation of timing recovery, carrier recovery, automatic gain control, and equalization functions.

Abstract: Various aspects and embodiments of the present invention derive statistics of received signal quality and use these statistics to jointly control operation of timing recovery, carrier recovery, automatic gain control, and equalization functions.

Abstract: Compensation methods and apparatus are disclosed for mitigating non-linear distortion of high power amplifiers used in communication transmitters, based on the minimization of the symbol error, in particular, for communication systems transmitting data embedded in existing co-channel signals. To overcome the difficulty of constructing pre-distortion mapping from the symbol error, an adaptive algorithm is disclosed to update compensation parameters for pre-distortion mapping. Another method exploits a test signal interval in the co-channel signal. During a known constant co-channel signal, distortion is estimated as a complex number and used to construct compensation parameters. The latter is further expanded by employing the adaptive algorithm for the non-test signal intervals.

Abstract: The present invention uses a novel adaptive soft decision device in order to jointly optimize decision device and DFE operation. The soft decision device receives the input and output samples of the slicer and generates a feedback sample by non-linearly combining them with respect to a single decision reference parameter. Moreover, the soft decision device provides novel error terms used to adapt equalizer coefficients in order to jointly optimize decision device and equalizer coefficients.

Abstract: Various aspects and embodiments of the present invention derive statistics of received signal quality and use these statistics to jointly control operation of timing recovery, carrier recovery, automatic gain control, and equalization functions.

Abstract: Lock state control is provided for the demodulator in a PCM receiver, including those demodulators using quadrature frequency shift keying, by selectively incrementally changing the phase of the received modulated carrier or of the "down converting" local oscillator. Switching means are provided to selectively shift the phase in multiples of 360/N degrees, where N is the number of available demodulation lock states, such as the number 4 in a quadri-phase system.

Abstract: The present invention uses a novel adaptive soft decision device in order to jointly optimize decision device and DFE operation. The soft decision device receives the input and output samples of the slicer and generates a feedback sample by non-linearly combining them with respect to a single decision reference parameter. Moreover, the soft decision device provides novel error terms used to adapt equalizer coefficients in order to jointly optimize decision device and equalizer coefficients.