Power control for TDMA mobile satellite communication system

In a mobile satellite communication system comprising a plurality of mobile terminals and a gateway earth station, a method for adjusting transmission power of a channel of the gateway earth station in communication with a first one of the mobile terminals comprising the steps of:

• broadcasting an upper threshold signal strength value, a lower threshold signal strength value, and a nominal signal quality value to the plurality of mobile terminals;
• measuring a received signal strength of a burst signal received from the gateway earth station by the first one of the plurality of mobile terminals;
• developing a signal quality value for said burst signal received by said first mobile terminal;
• setting a power control bit to a first value if said received signal strength is lower than said lower threshold signal strength value;
• setting said power control bit to a second value if said received signal strength is higher than said upper threshold signal strength value;
• setting said power control bit to the first value if said signal quality value is lower than said nominal signal quality value and said received strength signal is both higher than said lower threshold signal strength value and lower than said upper threshold signal strength value;
• setting said power control bit to the second value if said signal quality value is higher than said nominal signal quality value and said received strength signal is both higher than said lower threshold signal strength value and lower than said upper threshold signal strength value;
• transmitting said power control bit from the first mobile terminal to the gateway earth station;
• and,
• adjusting the transmission power of the channel of the gateway earth station in response to the power control bit.

In a mobile satellite communication system comprising a plurality of mobile terminals and a gateway earth station, a method for adjusting transmission power of a first one of the plurality of mobile terminals in communication with the gateway earth station comprising the steps of:

• broadcasting an upper threshold signal strength value, a lower threshold signal strength value, and a nominal signal quality value to the plurality of mobile terminals;
• measuring a received signal strength of a burst signal received from the first one of the plurality of mobile terminals by the gateway earth station;
• developing a signal quality value for said burst signal received by said gateway earth station;
• setting a power control bit to a first value if said received signal strength is lower than said lower threshold signal strength value;
• setting said power control bit to a second value if said received signal strength is higher than said upper threshold signal strength value;
• setting said power control bit to the first value if said signal quality value is lower than said nominal signal quality value and said received strength signal is both higher than said lower threshold signal strength value and lower than said upper threshold signal strength value;
• setting said power control bit to the second value if said signal quality value is higher than said nominal signal quality value and said received strength signal is both higher than said lower threshold signal strength value and lower than said upper threshold signal strength value;
• transmitting said power control bit from the gateway earth station to the first mobile terminal;
• and,
• adjusting the transmission power of the first mobile terminal in response to the power control bit.