Patent ID: 7974576
Filing Date: 2011-07-05
Classification: H04B,H04W

Abstract:
1. In a satellite communications network, wherein a power controlling hub terminal and a plurality of user terminals communicate through a communications relay satellite, a method of power control for a transmitter of a user terminal comprising: transmitting along a forward link from the hub terminal via the satellite to generate a forward link receive signal at the user terminal, the forward link receive signal experiencing forward link fading; thereafter transmitting along a return link from the user terminal via the satellite to generate a return link receive signal at the hub terminal, the return link receive signal experiencing return link fading; estimating the return link fading by monitoring the forward link receive signal at the user terminal; using a speed estimation during movement of the user terminal over a preselected distance to examine the forward link receive signal to correct for errors in estimation processes and to generate an open loop power correction value; transmitting an acknowledgement message over the forward link from the hub terminal to the user terminal; thereupon monitoring at the user terminal for whether or not the acknowledgement message has been received at the user terminal; and a) if the acknowledgement is received, updating a closed loop power correction at the user terminal with a received closed loop power correction value contained in the acknowledgement message; and b) if the acknowledgement message is not received, incrementing a closed loop power correction at the user terminal; thereupon adding the open loop power correction to the received closed loop power correction or the incremented closed loop power correction to yield a total power correction at the user terminal; and using the total power correction to adjust power level of the return link signal from the user terminal to the hub terminal.