Abstract: A laser communication crosslink system employs an nth order sigma delta modulator with a laser transmitter for communicating an analog input signal in binary form as a pulse width modulated signal, and employs a digital filter with a receiver for providing a digital output signal representing the value of the analog input signal. The pulse width modulated laser signal is communicated between the transmitter and receiver over a laser crosslink that may be fiber optic. The direct modulation using the sigma delta modulator with the transmitter and using the digital filter with the receiver reduces system complexity and power consumption.

Abstract: A method of determining communication link quality includes the steps of: providing communications stations (e.g., UHF communications satellites, base stations of a terrestrial cellular network) with beacon transmitters that are used to transmit two types of signals from each communications station; and providing a communications device that employs the communications stations with beacon receivers and the ability to process the two types of signals to provide a user of the communications device with a real time determination of link impairments and, from this, a determination of the type and quality of service that is available to the user. The first type of signal is a stable continuous wave (CW) tone that provides a reference signal level, and the second type of signal is a coded waveform with distinguishable correlation properties.

Abstract: A method of determining communication link quality includes the steps of: providing communications stations (e.g., UHF communications satellites, base stations of a terrestrial cellular network) with beacon transmitters that are used to transmit two types of signals from each communications station; and providing a communications device that employs the communications stations with beacon receivers and the ability to process the two types of signals to provide a user of the communications device with a real time determination of link impairments and, from this, a determination of the type and quality of service that is available to the user. The first type of signal is a stable continuous wave (CW) tone that provides a reference signal level, and the second type of signal is a coded waveform with distinguishable correlation properties.