Uplink power adjustment for a point-to-multipoint wireless communication system

摘要

In a point-to-multipoint wireless communication system including a master station and several terminal stations, adaptive PHY mode techniques for adaptively change both the modulation and the error correction code (FEC) are used. The master station includes means adapted to generate and transmit a broadcast message towards all the terminal stations to inform them about the power adjustments to be performed during a PHY mode switching. In particular two set of power corrections to be communicated to terminals are defined: one set informs the terminals on the power corrections when the PHY mode is downgraded, that is a switching towards a more robust and less efficient PHY mode is performed; the second set informs the terminals about power corrections when the PHY mode is upgraded to a more efficient and less robust one. Depending on the direction of the switching, upgrade or downgrade of the PHY mode, and depending on the new PHY mode the addressed terminal chooses the right value of power adjustment to correct the transmitted power. The message with the two set of power adjustments is broadcast to the terminals periodically, or when the master decides it's useful; no other messages are required in order to adjust the power during the switching of PHY modes. That is the terminals know in advance the power adjustment to apply to the transmitted power when they are instructed to perform the PHY mode switching (fig.1). <IMAGE>