Spread spectrum communication system and transmission power control method therefor
AssigneeFIPA Frohwitter Intellectual Property AG
InventorsTakashi Yano, Nobukazu Doi
Life of this patent
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Abstract
In a spread spectrum communication system, one (W.sub.n) of a series of orthogonal codes for spectrum spreading is assigned to signal-to-noise ratio measurement in a terminal. On the basis of a noise signal detected by de-spreading a signal received from an antenna with the above described orthogonal code (W.sub.n) and a pilot signal, each terminal derives a signal-to-noise ratio. Each terminal transmits the signal-to-noise ratio to the base station as a power control signal. On the basis of signal-to-noise information received from each terminal as the power control signal, the base station controls signal transmission power for each terminal.
Claims7
A method for controlling transmission, using spread spectrum communication techniques, of a data signal from a base station to a mobile terminal, the method comprising the steps of:
- transmitting, by the base station, a pilot signal in a given frequency band;
- receiving, by the mobile terminal, the transmitted pilot signal and generating a response signal in response to receiving the transmitted pilot signal, the response signal indicating a reception condition of said pilot signal at said mobile terminal;
- and
- receiving, by the base station, said response signal from the mobile terminal and controlling, within a transmission power range, a transmission power of said data signal transmitted to said mobile terminal in said frequency band in response to said received response signal,
- wherein the pilot signal is transmitted without transmission power control.
A base station for transmitting signals to a plurality of mobile terminals using spread spectrum communication techniques, said base station comprising:
- circuit components for transmitting a pilot signal;
- circuit components for receiving from at least one of said plurality of mobile terminals a control signal representative of a reception condition of said pilot signal at said at least one mobile terminal;
- and
- circuit components for analyzing said control signal received from said at least one mobile terminal and for controlling, within a transmission power range, the transmission power of a data signal transmitted to said at least one mobile terminal as a result of said analysis,
- wherein the pilot signal is transmitted without transmission power control.
A base station for transmitting signals to a plurality of mobile terminals using spread spectrum communication techniques, said base station comprising:
- circuit components for transmitting a pilot signal;
- circuit components for receiving from at least one of said plurality of mobile terminals a control signal representative of a reception condition of said pilot signal at said at least one mobile terminal;
- and
- circuit components for analyzing said control signal received from said at least one mobile terminal and for controlling, within a transmission power range, the transmission power of a data signal transmitted to said at least one mobile terminal as a result of said analysis,
- wherein said circuit components for receiving said signal representative of a reception condition of said pilot signal at said at least one mobile terminal are adapted to receive said control signal from said at least one mobile station indicating a reception condition of both said pilot signal and said data signal at said at least one mobile terminal, and
- wherein said data signal is transmitted to said at least one mobile terminal at a power inversely proportional to a signal-to-noise ratio being received at said base station as said control signal.
Dependencies are inferred from the claim text.