Transmitter power control method and apparatus

Abstract

Automatic control of the power of the transmitters ( and ) of a near-end-far-end transceiver pair ( ) is achieved by first determining whether the strength of the signals received at near-end and far-end receivers ( and ) of the near-end-far-end transceiver pair are simultaneously attenuated a prescribed value below received signal strength values measured during clear weather free-space conditions. If the received signal strengths are so attenuated, then transmission power of the near-end and far-end transceivers is increased by predetermined increments (or sequences or increments) to restore, but not exceed the strengths of the received signals to their respective signal strength values measured during clear weather free-space conditions. Conversely, if the above received signal strengths are determined not to be simultaneously attenuated by the said prescribed value, when one near-end or far-end received signal only is determined to be degraded (e.g., bit error ratio in excess of a given acceptable threshold value), then the transmission power of the far-end or near-end transceiver, respectively is increased either only sufficiently to restore the said degraded bit error ratio to acceptable, or until the predetermined upper limit of the allowable clear-weather transmitter power increase is reached. A variation of the latter limited automatic power control case (non-attenuated signals) accommodates the determination of degraded signals as received at both said transceivers, by increasing the transmission power of both said transceivers either only sufficiently to restore the said degraded bit error ratios to acceptable, or until the predetermined upper limit of the allowable clear-weather transmitter power increase is reached.