Adaptive power control for a spread spectrum communications system and method

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:

• 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.

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:

• 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.

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:

• 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.

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:

• 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.

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:

• 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.

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:

• 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.

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:

• 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.