Adaptive power control for a spread spectrum communications system and method
First Claim
1. A method for adaptive-power control of a plurality of spread-spectrum transmitters of a plurality of mobile stations, respectively, operating in a cellular-communications network using spread-spectrum modulation, each of said plurality of mobile stations having a transmitter, wherein a base station transmits a generic spread-spectrum signal, comprising:
- transmitting from said base station, on at least one of a continuous basis and a repetitive periodic basis, an adaptive-power control information signal comprising a digital power-level-referencing word having at least three bits, said word corresponding to a threshold having at least eight levels for a transmitter-power level of a mobile station;
acquiring the generic spread-spectrum signal and the adaptive-power control information signal at said mobile station;
decoding the adaptive-power control information signal as the threshold for the transmitter-power level of said mobile station;
detecting a received power level of the generic spread-spectrum signal at said mobile station;
generating, at said mobile station, a comparison signal by comparing the received power level to said threshold;
adjusting the transmitter-power level of said mobile station transmitter in response to said comparison signal; and
transmitting, from said mobile station, a spread-spectrum signal with the mobile station transmitter.
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Abstract
An apparatus for adaptive-power control of a spread-spectrum transmitter of a mobile station operating in a cellular-communications network using spread-spectrum modulation. A base station transmits a first spread-spectrum signal. A mobile station has an automatic-gain-control circuit for generating an AGC-output signal, from a received signal. The received signal includes the first spread-spectrum signal and an interfering signal. The mobile station also has a correlator for despreading the AGC-output signal, a power-measurement circuit responsive to processing the received signal with the despread AGC-output signal for generating a received-power level, a comparator coupled to the power-measurement circuit for generating a comparison signal by comparing the received-power level to a threshold level, a transmitter for transmitting a second spread-spectrum signal, an antenna, and a variable-gain device responsive to the comparison signal for adjusting a transmitter-power level of the second spread-spectrum signal.
93 Citations
15 Claims
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1. A method for adaptive-power control of a plurality of spread-spectrum transmitters of a plurality of mobile stations, respectively, operating in a cellular-communications network using spread-spectrum modulation, each of said plurality of mobile stations having a transmitter, wherein a base station transmits a generic spread-spectrum signal, comprising:
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transmitting from said base station, on at least one of a continuous basis and a repetitive periodic basis, an adaptive-power control information signal comprising a digital power-level-referencing word having at least three bits, said word corresponding to a threshold having at least eight levels for a transmitter-power level of a mobile station; acquiring the generic spread-spectrum signal and the adaptive-power control information signal at said mobile station; decoding the adaptive-power control information signal as the threshold for the transmitter-power level of said mobile station; detecting a received power level of the generic spread-spectrum signal at said mobile station; generating, at said mobile station, a comparison signal by comparing the received power level to said threshold; adjusting the transmitter-power level of said mobile station transmitter in response to said comparison signal; and transmitting, from said mobile station, a spread-spectrum signal with the mobile station transmitter. - View Dependent Claims (2, 3)
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4. A method for adaptive-power control of a spread-spectrum transmitter of a mobile station operating in a cellular-communications network, comprising the steps of:
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transmitting, from a base station, a first spread-spectrum signal; transmitting, from said base station, on at least one of a continuous basis and a repetitive periodic basis, an adaptive-power control information signal comprising a digital power-level-referencing word having a plurality of bits; receiving, at said mobile station, said adaptive-power control information signal and said first spread-spectrum signal; decoding said digital power-level-referencing word as a threshold for a transmitter-power level of said mobile station; inputting said first spread-spectrum signal to an automatic gain control circuit and to a power measurement circuit; generating, by the automatic gain control circuit and responsive to said first spread-spectrum signal, an automatic gain control-output signal; despreading the automatic gain control-output signal; inputting the despread automatic gain control-output signal to the power measurement circuit; processing, by the power measurement circuit, the first spread-spectrum signal with the despread automatic gain control-output signal for generating a received power level of the first spread-spectrum signal at said mobile station; generating, at said mobile station, a comparison signal by comparing the received power level to said threshold; adjusting, responsive to said comparison signal, the transmitter-power level of a second spread-spectrum signal; and transmitting, from said mobile station, the second spread-spectrum signal.
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5. A method for adaptive-power control of a spread-spectrum transmitter of a mobile station, using an open loop adaptive power control circuit, said method comprising the steps of:
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transmitting, from a base station, a first spread-spectrum signal; transmitting, from said base station, on at least one of a continuous basis and a repetitive periodic basis, an adaptive-power control information signal, the adaptive-power control information signal generated independently of mobile station input by the base station; receiving, at said mobile station, the first spread-spectrum signal as a received signal; inputting the received signal to an automatic gain control circuit and to a power measurement circuit; generating, by the automatic gain control circuit and responsive to the received signal, an automatic gain control-output signal; despreading the automatic gain control-output signal; inputting the despread automatic gain control-output-signal to the power measurement circuit; processing, by the power measurement circuit, the received signal with the despread automatic gain control-output signal to generate a received-power level; receiving, at said mobile station, the adaptive-power control information signal; decoding the adaptive-power control information signal as a threshold level; generating a comparison signal by comparing the received-power level to the threshold level; converting the comparison signal to a digital data signal; adjusting, using the digital data signal, a transmitter-power level of a second spread-spectrum signal; and transmitting, from said mobile station, the second spread-spectrum signal. - View Dependent Claims (8, 9)
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6. A method for adaptive-power control of a plurality of spread-spectrum transmitters of a plurality of mobile stations, operating in a cellular-communications network using spread-spectrum modulation, using an open loop adaptive power control circuit, said method comprising the steps of:
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transmitting, from a base station, a first spread-spectrum signal; transmitting, from said base station, on at least one of a continuous basis and a repetitive periodic basis, an adaptive-power control information signal; receiving, at each of said plurality of mobile stations, the first spread-spectrum signal as a received signal; processing the received signal to generate a received-power level; receiving at each of said plurality of mobile stations, on at least one of a continuous basis and a repetitive periodic basis, the adaptive-power control information signal; decoding the adaptive-power control information signal as a first threshold level; generating a comparison signal by comparing the received-power level to the first threshold level; converting the comparison signal to a digital data signal; adjusting, using the digital data signal, at each of said plurality of mobile stations, a transmitter-power level of a respective second spread-spectrum signal; transmitting, from each of said plurality of mobile stations, the second spread-spectrum signal; adjusting, at the base station, the adaptive-power control information signal as an adjusted-adaptive-power control information signal having a second threshold value; transmitting the adjusted-adaptive-power control information signal; and receiving and decoding, at each of said plurality of mobile stations, the adjusted-adaptive-power control information signal as the second threshold value.
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7. A method for adaptive-power control of a plurality of spread-spectrum transmitters of a respective plurality of mobile stations, using an adaptive power control-data signal from a base station, the method comprising the steps of:
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transmitting, from the base station, a first spread-spectrum signal; transmitting, from the base station, on at least one of a continuous basis and a repetitive periodic basis, a first adaptive power control-data signal; receiving, by a mobile station, the first spread-spectrum signal; despreading, at the mobile station, the first spread-spectrum signal with a first chip-code signal;
filtering the despread first spread-spectrum signal through a bandpass filter;
measuring a first received power level of the despread first spread-spectrum signal;receiving the first adaptive power control-data signal at the mobile station; decoding the first adaptive power control-data signal to obtain a value of a first threshold level; comparing the first received power level of the despread first spread-spectrum signal to the first threshold level; decreasing, responsive to the first received power level being greater than the first threshold level, a power level of a second spread-spectrum signal; increasing, responsive to the first received power level being less than the first threshold level, a power level of the second spread-spectrum signal; transmitting the second spread-spectrum signal; transmitting, from the base station, a third spread-spectrum signal; transmitting, from the base station, on at least one of a continuous basis and a repetitive periodic basis, a second adaptive power control-data signal; receiving, by a mobile station, the third spread-spectrum signal; despreading, at the mobile station, the third spread-spectrum signal with a second chip-code signal; filtering the despread third spread-spectrum signal through a bandpass filter; measuring a second received power level of the despread third spread-spectrum signal; receiving the second adaptive power control-data signal at the mobile station; decoding the second adaptive power control-data signal to obtain a value of a second threshold level; comparing the second received power level of the despread third spread-spectrum signal to the second threshold level; decreasing, responsive to the second received power level being greater than the second threshold level, a power level of a fourth spread-spectrum signal; increasing, responsive to the second received power level being less than the second threshold level, a power level of the fourth spread-spectrum signal; and transmitting the fourth spread-spectrum signal.
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10. A method for adaptive-power control of a spread-spectrum transmitter for a mobile station operating in a cellular-communications network using spread-spectrum modulation and an open-loop adaptive power control circuit, the method comprising the steps of:
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transmitting, from a base station, a first spread-spectrum signal; transmitting, from said base station, on at least one of a continuous basis and a repetitive periodic basis, an adaptive-power control information signal; receiving, at the mobile station, the first spread-spectrum signal transmitted from said base station; detecting a received power level of the received first spread-spectrum signal; receiving, at the mobile station, the adaptive power control information signal as a threshold level; comparing the received power level to the threshold level; adjusting a transmitter power level of a second spread-spectrum signal in response to said comparison; and transmitting the second spread-spectrum signal. - View Dependent Claims (11)
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12. An apparatus for dynamic adaptive-power control of a spread-spectrum transmitter of a mobile station operating in a cellular communications network using spread-spectrum modulation and an open-loop adaptive power control circuit, comprising:
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a base station for transmitting a generic spread-spectrum signal and for transmitting, on at least one of a continuous basis and a repetitive periodic basis, an adaptive power control signal, the adaptive-power control signal containing a threshold value, the threshold value independently determined by the base station; a plurality of mobile stations, each of said plurality of mobile stations having, an acquisition circuit for receiving the generic spread-spectrum signal and the adaptive power control signal; a detector coupled to said acquisition circuit for detecting a received power level of the received generic spread-spectrum signal; a decoder, coupled to said acquisition circuit, for decoding, on at least one of a continuous basis and a repetitive periodic basis, the received adaptive power control signal as the threshold; a differential amplifier, coupled to said detector and to said decoder, for generating a comparison signal by comparing the received power level to the threshold; a transmitter for transmitting a transmitter spread-spectrum signal; an antenna coupled to said transmitter; and a variable-gain device coupled between said differential amplifier and said transmitter, responsive to said comparison signal indicating at least one of an increase and a decrease, for adjusting a transmitter-power level of the transmitter spread-spectrum signal from said transmitter. - View Dependent Claims (14, 15)
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13. An apparatus for adaptive-power control of a spread-spectrum transmitter of a mobile station operating in a cellular-communications network using spread-spectrum modulation, wherein a base station transmits, on at least one of a continuous basis and a repetitive periodic basis, an adaptive power control data signal and a generic spread-spectrum signal, said mobile station comprising:
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acquisition means for receiving the generic spread-spectrum signal and the adaptive power control-data signal; decoder means, coupled to said acquisition means, for decoding, on at least one of a continuous basis and a repetitive periodic basis, the received adaptive power control-data signal as a threshold level; automatic gain control means, coupled to said acquisition means, for generating, responsive to the received generic spread-spectrum signal, an automatic gain control-output signal; correlator means, coupled to said automatic gain control means, for despreading the automatic gain control-output signal; power means, coupled to said correlator means, for processing the received generic spread-spectrum signal with the despread automatic gain control-output signal, for generating a received-power level; comparator means, coupled to said decoder means and to said power means, for generating a comparison signal by comparing the received-power level to said threshold level; transmitter means for transmitting a transmitter spread-spectrum signal; an antenna, coupled to said transmitter means, for radiating the transmitter spread-spectrum signal; and variable-gain means, coupled between said comparator means and said transmitter means, responsive to said comparison signal indicating at least one of an increase and a decrease, for adjusting a transmitter-power level of the transmitter spread-spectrum signal of said transmitter means.
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Specification