Abstract: A Finite Impulse Response (FIR) filter that reduces the complexity of the hardware required for a filter with a high decimation factor while achieving similar performance of prior art poly-phase filters of greater complexity. The FIR filter includes a small number of multiply-and-accumulate (MAC) units connected in parallel to each other between an input stream and an output stream. The MAC units are provided with coefficients from a memory. In an example implementation, the memory is addressed by a counter and the output of the memory selected by a multiplexer for suppling the coefficients.

Abstract: Digital pre-distorter (DPD) coefficients can be used to compensate for non-linearity of a power amplifier (PA). A system can receive a defined waveform from transmit hardware. The system can transmit an output waveform with a defined modulation from the PA. The system can capture samples of the output waveform. The system can submit the samples to a processing system temporarily connected to a transmitter system. The system can compute a PA model using the defined waveform and the samples. The system can determine a plurality of Digital Pre-Distorter (DPD) coefficients for a plurality of power levels, frequencies, and temperatures based on the PA model. The system can store the plurality of DPD coefficients to a memory of the transmitter system. Additionally, the system can add predistortions using the plurality of DPD coefficients to a plurality of input waveforms to correct for impairments introduced by the PA.

Abstract: A method for communicating with a legacy terminal supporting a legacy air interface and a new terminal supporting a next generation air interface including: assigning a same carrier to the legacy terminal and the new terminal; receiving a terminal identifier and an optional payload for transmission at a MAC/RLC layer; determining if the terminal identifier is associated with the legacy terminal or the new terminal; composing, based on the determining, a burst header; formatting, a burst including the burst header and the optional payload; and transmitting the burst. In the method, the burst header is set to one of the one or more valid burst headers when the burst is associated with the legacy terminal, and the burst header is set to one of the one or more undefined burst headers when the burst is associated with the new terminal.

Abstract: A method for communicating with a legacy terminal supporting a legacy air interface and a new terminal supporting a next generation air interface including: assigning a same carrier to the legacy terminal and the new terminal; receiving a terminal identifier and an optional payload for transmission at a MAC/RLC layer; determining if the terminal identifier is associated with the legacy terminal or the new terminal; composing, based on the determining, a burst header; formatting, a burst including the burst header and the optional payload; and transmitting the burst. In the method, the burst header is set to one of the one or more valid burst headers when the burst is associated with the legacy terminal, and the burst header is set to one of the one or more undefined burst headers when the burst is associated with the new terminal.

Abstract: A Finite Impulse Response (FIR) filter that reduces the complexity of the hardware required for a filter with a high decimation factor while achieving similar performance of prior art poly-phase filters of greater complexity. The FIR filter includes a small number of multiply-and-accumulate (MAC) units connected in parallel to each other between an input stream and an output stream. The MAC units are provided with coefficients from a memory. In an example implementation, the memory is addressed by a counter and the output of the memory selected by a multiplexer for suppling the coefficients.

Abstract: A method for communicating with a legacy terminal supporting a legacy air interface and a new terminal supporting a next generation air interface including: assigning a same carrier to the legacy terminal and the new terminal; receiving a terminal identifier and an optional payload for transmission at a MAC/RLC layer; determining if the terminal identifier is associated with the legacy terminal or the new terminal; composing, based on the determining, a burst header; formatting, a burst including the burst header and the optional payload; and transmitting the burst. In the method, the burst header is set to one of the one or more valid burst headers when the burst is associated with the legacy terminal, and the burst header is set to one of the one or more undefined burst headers when the burst is associated with the new terminal.

Abstract: Disclosed methods of terrestrial station monitoring of downlink signal quality include receiving a sequence of samples of reference symbol slots of a downlink burst, and estimating a time offset between a local clock and a timing of a symbol pattern carried by the reference symbol slots, using a local copy of the reference symbol pattern. A corresponding time correction is applied to the sequence of samples to form time corrected samples of symbols carried by the reference symbol slots. A frequency offset between the time corrected samples of the symbols carried by the reference symbol slots and a local clock is estimated. A corresponding frequency compensation is applied to the time corrected samples, forming time/frequency compensated samples of the symbols carried by the reference symbol slots. A signal to noise plus interference ratio (SNIR) estimation data, and corresponding estimate of signal path, is generated, based on moments of the time/frequency compensated samples.

Abstract: Disclosed methods of terrestrial station monitoring of downlink signal quality include receiving a sequence of samples of reference symbol slots of a downlink burst, and estimating a time offset between a local clock and a timing of a symbol pattern carried by the reference symbol slots, using a local copy of the reference symbol pattern. A corresponding time correction is applied to the sequence of samples to form time corrected samples of symbols carried by the reference symbol slots. A frequency offset between the time corrected samples of the symbols carried by the reference symbol slots and a local clock is estimated. A corresponding frequency compensation is applied to the time corrected samples, forming time/frequency compensated samples of the symbols carried by the reference symbol slots. A signal to noise plus interference ratio (SNIR) estimation data, and corresponding estimate of signal path, is generated, based on moments of the time/frequency compensated samples.

Abstract: A telecommunications system includes a satellite receiver programmed to estimate a Doppler frequency associated with a satellite signal. Estimating the Doppler frequency includes sampling the satellite signal, resampling the sampled satellite signal, and compensating for a frequency offset associated with the satellite signal. An example satellite receiver includes a sampling device programmed to sample the satellite signal, a resampling device programmed to sample the sampled satellite signal and output a resampled satellite signal, and an incremental phase modulator programmed to filter a frequency offset from the resampled satellite signal.

Abstract: A numerically controlled oscillator includes a phase accumulator that outputs a phase word and a clock that periodically outputs a clock signal in accordance with a delay interval. The phase accumulator outputs a new phase word in response to receiving the clock signal. A clock controller calculates a timing drift and adjusts the delay interval to reduce the timing drift. A method includes receiving a plurality of frequency control words, calculating a delay interval, accumulating the frequency control words in accordance with the delay interval to generate a phase word, converting the phase word to a waveform, calculating a timing drift, and adjusting the delay interval to reduce the timing drift.

Abstract: A telecommunications system includes a satellite receiver programmed to estimate a Doppler frequency associated with a satellite signal. Estimating the Doppler frequency includes sampling the satellite signal, resampling the sampled satellite signal, and compensating for a frequency offset associated with the satellite signal. An example satellite receiver includes a sampling device programmed to sample the satellite signal, a resampling device programmed to sample the sampled satellite signal and output a resampled satellite signal, and an incremental phase modulator programmed to filter a frequency offset from the resampled satellite signal.

Abstract: A numerically controlled oscillator includes a phase accumulator that outputs a phase word and a clock that periodically outputs a clock signal in accordance with a delay interval. The phase accumulator outputs a new phase word in response to receiving the clock signal. A clock controller calculates a timing drift and adjusts the delay interval to reduce the timing drift. A method includes receiving a plurality of frequency control words, calculating a delay interval, accumulating the frequency control words in accordance with the delay interval to generate a phase word, converting the phase word to a waveform, calculating a timing drift, and adjusting the delay interval to reduce the timing drift.

Abstract: A numerically controlled oscillator includes a phase accumulator configured to output a phase word, a clock configured to periodically output a clock signal in accordance with a delay interval, and a clock controller configured to adjust the delay interval. The phase accumulator is configured to output a new phase word in response to receiving the clock signal. An example method includes receiving a plurality of frequency control words, calculating a delay interval, accumulating the frequency control words in accordance with the delay interval to generate a phase word, and converting the phase word to a waveform.

Abstract: A facsimile transmission relay apparatus, referred to as an Intelligent Facsimile Relay (IFR) for improving call success rates in long delay environment such as terrestrial cellular, fixed wireless, and geostationary mobile satellite systems and the like. A first bi-directional telecommunications interface is provided for receiving facsimile signals from a transmitting facsimile device via a first network such as a Public Switch Telephone Network (PSTN). A buffer memory is used by the IFR for storing the facsimile signal, and a second bi-directional telecommunications interface retransmits the facsimile signal via the second network, e.g., a wireless network, to a receiving facsimile device to avoid signal collisions between the devices.