Automatic power control system for a code division multiple access (CDMA) communications system
AssigneeInterDigital Technology Corporation
InventorsGary Lomp, Fatih Ozluturk, John Kowalski
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Abstract
A receiver receives signals and noise over a frequency spectrum of a desired received signal. The desired received signal is spread using code division multiple access. The received signals and noise are demodulated to produce a demodulated signal. The demodulated signal is despread using a code uncorrelated with a code associated with the desired received signal. A power level of the despread demodulated signal is measured as an estimate of the noise level of the frequency spectrum.
Claims14
A method of Maintenance Power Control (MPC) for a subscriber unit (SU) which conducts wireless communication with a base station in a wireless communication system, the method comprising:
- providing a transmitter having an awake phase for transmitting signals to a base station which are initialized at a selected initial power level and a powered down sleep phase;
- when in said sleep phase, periodically activating the transmitter to transmit a status signal;
- and
- adjusting the selected initial power level downwardly when a reply signal is received and upwardly when no reply signal is received within a predetermined time period of the transmission of a status signal whereby the selected initial power level is maintained at a level for efficient system communications.
A subscriber unit (SU) having Maintenance Power Control (MPC) for wireless communication with a base station in a wireless communication system, the SU comprising:
- a transmitter having an awake phase for transmitting signals to a base station which are initialized at a selected initial power level and a powered down sleep phase;
- a receiver and associated MPC circuitry for controlling the selected initial power level of said transmitter;
- said transmitter, when in said sleep phase, configured to become periodically active to transmit a status signal;
- and
- said receiver and associated MPC circuitry configured to adjust the selected initial power level downwardly when a reply signal is received and upwardly when no reply signal is received within a predetermined time period whereby the selected initial power level is maintained at a level for efficient system communications.
Dependencies are inferred from the claim text.